Have tried to find some good guide for it but where?
[img]http://www.famicomworld.com/forum/index.php?action=dlattach;topic=4688.0;attach=896;image[/img]
There you go as provided by another member on here, it seems a bit to big though.
Mod edit:
I was told that the original picture here was totally wrong. Use the following site instead:
http://jpx72.detailne.sk/modd_files/fc/avmod.htm (http://jpx72.detailne.sk/modd_files/fc/avmod.htm)
awsome thanks
Remember we are not responsible for your console no longer functioning after the mod; you take full responsibility if it doesnt work.
Looks risky and if it's done wrongly the console ends up having malfunction which isn't good at all.
Good luck SF84 if you're going to do it.
There's only 4 solder points on the Famicom board itself. It's not really risky at all if you're careful and double-check your work. If it doesn't work right the first time, go back and check your work and make the appropriate fixes. It's a game console, not a pipe bomb. :P
I draw it just to make it look easier. Guess it didn't help :P
It's very simple though, You can check the finished PCB on my web site:
http://jpx72.detailne.sk/modd_files/fc/avmod.htm (http://jpx72.detailne.sk/modd_files/fc/avmod.htm)
EDIT: On my webpage is the most recent and most perfectly working schematics provided by a member named kyuusaku. Feel free to try it!
Quote from: jpx72 on May 02, 2010, 01:48:37 am
I draw it just to make it look easier. Guess it didn't help :P
It's very simple though, You can check the finished PCB on my web site:
http://jpx72.detailne.sk/modd_files/fc/avmod.htm (http://jpx72.detailne.sk/modd_files/fc/avmod.htm)
That PCB you made is quite nice.
That is really awesome looking, and very professional-like. I would be impressed by such a mod.
I have done some testing (thanks to marqs from NFGGames.com) and I have changed my schematics to work properly with any famicom (the last one has brightness dropping issues on older PCBs). Also I love his idea of adding the capacitor to PPU - that's a signifficant improvement (reducing the brighter vertical bars)!!!
Check my webpage (http://jpx72.detailne.sk/modd_files/fc/avmod.htm) or look on the attached schematics only.
This schematics is universal (because different Famicom boards have different parts). Isolating the pin 21 of PPU from the PCB isn't necessary.
EDIT: If you experience very bright image, try to experiment with the 2,2k ohm resistor connected to +5V. Try to exchange it with lower ohm resistor, but not lower than 500 ohm!
As I am writing on my webpage, you can use the transistor on your Famicom PCB instead of adding a new one. But to make this schematics universal (and completelly detachable), I am sugesting to build this schematics outside od famicom and connect it directly to pin#21 on PPU.
PS: my old schematics suggested 10uF capacitor between pin21 and transistor. But this only worked on HVC-CPU-GPM-02. So I removed it from this one.
This= awesome
One question though
What other transistors would work with this?
Any standard transistor, type: PNP, "Bipolar junction transistor (BJT)", hard to say if it's low/medium/high frequency, because there are various definitions, but around 150 MHz it's ok. Original famicom has type 2SA*****, what, according to wikipedia, is "high frequency PNP BJTs". But if you ask in local electronics shop, I'm sure they will help you. Ask for PNP transistor for 5V (and more).
If I remember right, Radio Shack didn't have it so I just ordered a bag of maybe a hundred of them off of eBay.
Thanks ;)
QuoteAlso I love his idea of adding the capacitor to PPU - that's a signifficant improvement (reducing the brighter vertical bars)!!!
Empirically the bars are interference from the address bus, you don't need to put a giant-cap on your PPU to lose it.
QuoteEDIT: If you experience very bright image, try to experiment with the 2,2k ohm resistor connected to +5V. Try to exchange it with lower ohm resistor, but not lower than 500 ohm!
Any time someone has to experiment in a non-RF circuit there's something wrong. These "AV mods" are common-collector amplifiers so they simply buffer the voltage on the video pin. Your 2.2k / 220 R combo is setting the level too high in parallel with the TV's 75 ohm load. You only need to connect the emitter to the supply though a 300 ohm, and the output cap to the emitter.
I don't know the purpose for the 560p shunt cap, it's creating a low-pass filter with a Fc of 2.58 MHz... Since video is 6 MHz it's doing a bit of harm. I'd think it'd make it blurry...
QuotePS: my old schematics suggested 10uF capacitor between pin21 and transistor. But this only worked on HVC-CPU-GMP-02. So I removed it from this one.
The capacitor is only necessary/only works when using a NPN transistor since the PPU doesn't source current, it sinks it. Using a PNP sources current for the PPU directly.
Quote from: kyuusaku on September 19, 2010, 01:26:31 am
QuoteAlso I love his idea of adding the capacitor to PPU - that's a signifficant improvement (reducing the brighter vertical bars)!!!
Empirically the bars are interference from the address bus, you don't need to put a giant-cap on your PPU to lose it.
QuoteEDIT: If you experience very bright image, try to experiment with the 2,2k ohm resistor connected to +5V. Try to exchange it with lower ohm resistor, but not lower than 500 ohm!
Any time someone has to experiment in a non-RF circuit there's something wrong. These "AV mods" are common-collector amplifiers so they simply buffer the voltage on the video pin. Your 2.2k / 220 R combo is setting the level too high in parallel with the TV's 75 ohm load. You only need to connect the emitter to the supply though a 300 ohm, and the output cap to the emitter.
I don't know the purpose for the 560p shunt cap, it's creating a low-pass filter with a Fc of 2.58 MHz... Since video is 6 MHz it's doing a bit of harm. I'd think it'd make it blurry...
QuotePS: my old schematics suggested 10uF capacitor between pin21 and transistor. But this only worked on HVC-CPU-GMP-02. So I removed it from this one.
The capacitor is only necessary/only works when using a NPN transistor since the PPU doesn't source current, it sinks it. Using a PNP sources current for the PPU directly.
Any chance for a schematic? :)
thanks
This is what the AV FC uses, simplified to remove over-engineering:
Hmm thanks for the suggestions on removing the unnecessary parts from my schematics, but is it not too much for the transistor to handle if there is only 300 ohm resistor on +5V? I think it depends on transistor type though... The small cap is removing only the highest peaks on the output, the image will not be blurry, but the extreme sharpness will be reduced (barely visible).
Quote from: kyuusaku on September 19, 2010, 01:26:31 am
Empirically the bars are interference from the address bus, you don't need to put a giant-cap on your PPU to lose it.
And what do you suggest to remove these bars? Because giant cap works like charm.
Quote from: jpx72 on September 19, 2010, 10:26:20 pm
Quote from: kyuusaku on September 19, 2010, 01:26:31 am
Empirically the bars are interference from the address bus, you don't need to put a giant-cap on your PPU to lose it.
And what do you suggest to remove these bars? Because giant cap works like charm.
Completely isolating PPU pin 21 from the printed circuit board, using shielded (coax) cable to keep the video signal from being "contaminated" with computer noise.
Quote from: 133MHz on September 19, 2010, 10:56:00 pm
Completely isolating PPU pin 21 from the printed circuit board, using shielded (coax) cable to keep the video signal from being "contaminated" with computer noise.
Isolation not working, tried that. Shielded cable, maybe... Giant cap - 100% working (without isolation of pin 21 and with any cable). Maybe the signal is already contaminated when outputing from PPU because of the power adaptor and/or other components on PCB connected to PPU...
QuoteHmm thanks for the suggestions on removing the unnecessary parts from my schematics, but is it not too much for the transistor to handle if there is only 300 ohm resistor on +5V?
The transistor can handle a lot more current, over 10x. Worst case the PPU level will be from 0.7V-1.7V = <17mA .
QuoteThe small cap is removing only the highest peaks on the output, the image will not be blurry, but the extreme sharpness will be reduced (barely visible).
What's the point of it though? The reason it's not terribly noticeable is because the filter has such poor roll-off. It is affecting the high frequency components, particularly color information.
I'm not sure how to best solve the bar problem, my stock FC/AVFC don't have it. Some clones and AV-modded units I've had do. As best I can tell this has something to do with the board layout. The bars appear every 8 background pixels right? This corresponds to the toggling of PPU A7.
Quote from: kyuusaku on September 20, 2010, 02:50:06 am
The bars appear every 8 background pixels right? This corresponds to the toggling of PPU A7.
Oh I can't say if it's every 8 pixels, but probably yes. My point is that the solution IS adding the capacitor, on my FC with HVC-CPU-07 board - with added 820uF cap - the picture is nearly perfect, the bars are not visible at all. So a definite solution for people that know nothing about electronics at all.
Agreed to that small cap though, let's drop it :)
So you are puting the 820 cap instead of the 220 right?
NO, I am using 820uF instead of 1000uF cap which is placed between pin 20 and 40 of PPU (not on the schematics!) for getting rid of the white bars (a common issue of AV modded famicom).
On the schematics: I am not replacing the 220uF cap. BUT you can replace the 2,2k RESISTOR with something lower, like 0,5k (500ohms) when you have brightness-lowering issues. This depends on the type uf transistor you use.
Check my page for altered schematics and to get rid of the confusion. http://jpx72.detailne.sk/modd_files/fc/avmod.htm
Ah right, ok thanks ;) When i first checked the site i stopped at the schematic and never went down to the bottom, my bad :P
Post Merge: September 23, 2010, 03:04:56 pm
Ok, so i just finished my mod and i am amazed how good the picture quality is.
Its clear, sharp, and best of all no ghost lines :o
To be honest i was expecting to have the ghost lines, as i did not add the 820uF cap( as i couldn't find one). So im guessing the ghost line problem varies from famicom to famicom, some have it, some don't.
One more thing to note is that i used a 2N3906 transistor. If i have the time i'll probably try it with the 2sa937, but i don't think that it will have a big impact on the end result.
Bottom line, use a 300 ohm resistor and drop the 560pF cap. ;)
Congratulations to your mod lillin!
Your transistor has slightly higher max frequency (250 instead of 140MHz) and collector current (IC=200mA instead of 100mA) than the 2SA***. Have you added the 220ohm resistor between emittor and 220uF cap or just did the kyuusaku's schematics? And did you solder your video output on the pin #21 of the PPU?
What PCB model you have?
I did kyuusaku's schematic.
And yes i soldered it to pin 21 on the ppu.
The board was a HVC-CPU-07.
It almost doesn't matter which transistor you use in this case, in fact it's best to use 2N3906 because it's the most common PNP and cheapest (in the US, UK should use BC556 or something). The frequency also really doesn't matter (as long as you're not using a power transistor) because frequency depends on gain, and in this amplifier the gain is 1 (ie. no gain) and a video signal is only 6 MHz.
I wonder if the lines are a flaw inherent to the earlier PPU revisions...or just a weak signal path on the PCB. I note that they are quote noticeable on my C1, and on a couple modded FCs, but I don't think any of them are the HVC-GMP version. I need to look at how the composite video is set up on the Sharp AN-xx series to see how it differs from the HVC-101.
I guess the real question is: What causes the 'jair bars' int he first place? I think it's a PPU design issue, but I guess it could be a signal strength or sync problem (?).Additionally, what is the inherent benefit of drawing video off the PPU directly, rather than after the 220 Ohm resistor? I would think the latter to be better, but I'm not sure.
It's none of those those things. Reading comprehension.
I did the mod using kyuusaku's schematic and I get the "jail bars" :( they are really bad especially on a blue background. they look just as bad as the nes2 vertical lines.
Which board do you have? If you have the one with the clearly labeled VCC GND SOU and VIDEO, then this thread may help http://www.famicomworld.com/forum/index.php?topic=3924.15 (http://www.famicomworld.com/forum/index.php?topic=3924.15)
I've found another interesting schematics, on the Polish forum (http://www.forum.emunes.pl) by a member dic-sc7
http://www.forum.emunes.pl/index.php?topic=3381.0
(the FC means ferrit-circle)
EDIT: According to the author, this schematics is his own AV-Mod design.
I used your schematic jpx72, and I'm not getting any video signal. Sound works perfectly though. :) Could you help me out?
Some things that could be the problem:
-I used Q1 on the board as my transistor
-I connected a 10k resistor and 100k resistor together because I didn't have a 110k resistor.
I know the solder connections are solid, as I used a multimeter and got current going through every connection.
I can include a picture of the circuit if necesary.
Quote from: zmaster18 on December 29, 2010, 09:25:33 pm
I used Q1 on the board as my transistor
I think that's your problem. Did you actually desolder it from the board, or did you just solder your connections to it without removing it? If you didn't remove it, you should cut the traces connected to the transistor pins.
Hmm no, I'm using the on-board transistor as well without any cuting or desoldering. What type of famicom do you have (pcb model number)? And how do you connected those resistors? Because if you connect them parallel, the ohmage is not calculated together... BUT there is no 110k resistor! It's 110 ohm (not 110000)!
ah, it's 110 ohm! I'll go check my parts to see if I have it. I'm a beginer with electronics, so what I did with the resistors made sense in my head!! :P
As for the transistor, I noticed that the video signal was already connected because its trace leads to the video pin on the PPU.
Well, I'm gonna give this another go. Thanks for the advice!
If you cannot find it, try it without it.
Alright, I replaced the resistors and now have video. The colours are kinda off - Mario's sleeves are green instead of brown. I tried different resistors ranging from 500 - 2200 ohms, used a different capacitor, and still no difference. The only thing I haven't changed is the ceramic disk capacitor which is 560pf.
Hmm at least some success.. I know now, that my schematics isn't so universal, and I have seen so many designs lately... What PCB do you have (the white number/code on the components side)? Only thing I can advise you now is to try your own transistor instead of the built-in one, and take the video signal directly from pin 21 of PPU, and also the resistor of choice - try using the lowest range (or lower, like 300). But don't cut/desolder anything on the famicom board, it can be done without it, be patient.
Maybe using the other schematics (not reffering to anything in particular) with NPN transistor is more universal. OR - one member here is onto something lately, trying to bring the AV mod to perfection, so maybe you can wait for a little while to see what he will come out with.
So it's the transistor? I only have two other ones: C1815 and S9015. I remember reading somewhere about the C1815 being used.
The S9015 is PNP (if I am reading the datasheets right) . C1815 is NPN. So for my schematics you will need the S9015.
Quote from: jpx72 on October 29, 2010, 12:53:47 am
I've found another interesting schematics, on the Polish forum (http://www.forum.emunes.pl) by a member dic-sc7
This circuit is pretty bad too, it seems anyone will just post anything...
TO EVERYONE, HERE IS THE BOTTOM LINE: The video output by the PPU is READY for connection to a TV. It is a *PERFECT* signal which doesn't need "cleaning". The only reason for a transistor is to buffer the signal and match impedances. When you use these crazy circuits which are clearly not designed by video engineers you do one or more of the following:
-create filters which reduce the horizontal resolution
-create filters which result in the loss of color information
-amplify the signal and brighten the image
-attenuate the signal and darken the image
"Jailbars" are caused by interference, probably on the chip's power rails. Using different exotic video amplifier circuits will not fix this issue.
Quote(the FC means ferrit-circle)
It's not circle but CHOKE. A choke is an inductor to pass DC and block AC and it's not really desirable here.
Thanks kyuusaku, can't argue with that, but:
Quote from: kyuusaku on December 31, 2010, 01:53:04 pm
-create filters which reduce the horizontal resolution
-create filters which result in the loss of color information
-amplify the signal and brighten the image
-attenuate the signal and darken the image
-this is what we're trying to do and as you can see we are not good at it. If you want to be of help, propose a schematics to built those. I think everyone involved would be really gratefull if you do that. Really. Please.
So all I need to do is wire it up with a transistor? Why haven't I seen this done before?
Quote from: jpx72 on January 01, 2011, 05:46:19 am
Thanks kyuusaku, can't argue with that, but:
Quote from: kyuusaku on December 31, 2010, 01:53:04 pm
-create filters which reduce the horizontal resolution
-create filters which result in the loss of color information
-amplify the signal and brighten the image
-attenuate the signal and darken the image
-this is what we're trying to do and as you can see we are not good at it. If you want to be of help, propose a schematics to built those. I think everyone involved would be really gratefull if you do that. Really. Please.
I posted what I believe is the best circuit 1 page pack. It's a single PNP, 2 resistors and 1 cap. Since I posted that I believe it's better to switch the position of the output resistor and capacitor.
So this is it: (attachment)
zmaster18 - try to build this one. Use the S9015 transistor (PNP).
Ok, so I played around with the circuit, and got video that is 90% accurate. I'm satisfied with it.
Now, my next question: I used a Nintendo AV connector from a Gamecube. I want to mount it right where the TV/Game switch is. How do I go about removing parts of the RF Modulator? I don't need to have it working, since it doesn't work anyways. My Famicom is HVC-CPU-007.
kyuusaku I have built your simple schematics and can confirm that it works better than any other experiment. But the vertical bars are still a problem (even if using fully shielded cables and everything is built right on the PCB of the famicom so really close together to minimise interference). But by adding the 500microF capacitor between PPU's GND and VCC pins the problem disappears.
(I have also updated my page with that schematics, I hope you won't mind http://www.jpx72.detailne.sk/modd_files/fc/avmod.htm)
I just completed jpx72's AV mod with success! I'd like to suggest that someone add the wattage and voltage requirements for the various capacitors, resistors, etc. as I had to buy several sets to get them to work. Eventually I used 1/2 watt for the resistors and 25V for the main capacitor and it worked just great. Thanks!
I also made this mod and it's working great! I didn't put a capacitor over the PPU since it didn't make any difference.
(http://www.gnys.se/da_bear/famicom/DSC_9129.jpg)
(http://www.gnys.se/da_bear/famicom/DSC_9124.jpg)
Thanks, but it was kyuusaku that made that schematic, I only put it together with some explanatory pictures...
So give him credit as deserved, and meanwhile - great work guys and thanks for the feedback!
Okey, so I have done a slight modification to this mod.
First I used a 2N3906 PNP transistor as kyuusaku suggested earlier in this thread. The mod worked great with this, but not good enough (slighty blurred image and 'jailbars')
So, I desoldered the 2SA937 from the Famicom(Q1 next to PPU) and replaced my 2N... with the 2SA...
Next I cut the trace from PPU pin #21 and Q1. I cut it in both ends.
Result:
# Crisp and clear image, no blur whatsoever.
# No more jailbars! Yey! If you know they are there, you can see them - barely. Almost completely gone! No need for capacitor over the PPU!
Try it! No need for RGB mod :D
Well that's good for you! :D
Maybe cutting #21 and desoldering that transistor does help because I tried this mod without desoldering the 2SA937 (Q1) from the board, I used this transistor directly, I just cut the emitor and continued with the rest of the schematics from there (collector is already on GND and #21 is on base) but without luck in better image.
It all depends on the whole thing built, the quality of soldering etc. And of course on the mainboard model. By the way, which board do You have?
I have a 02F board.
First I just cut the trace without removing the 2SA937, but that alone didn't do anything to reduce the jailbars. It was after I removed 2SA... the 'jailbars' was heavily reduced.
The reason for this is as I understand, that the trace from #21 to Q1 picks up interference from the databus right below.
And it's possible that the 2SA937 isn't so sensitive to interference as the 2N3906 and it's equivalents.
Here are some images, I know some of you (including me) want see what we're talking about :)
First the location of Q1 seen from top, here I have already removed it but it's easy to locate.
(http://www.gnys.se/da_bear/famicom/DSC_9242.jpg)
Here you see wich trace to cut. Be careful so you don't cut any other trace as this will destroy your Famicom.
I scraped the trace in the middle and used a multimeter to make sure the trace was really disconnected.
(http://www.gnys.se/da_bear/famicom/DSC_9249.jpg)
Not the best image, but here I have replaced my 2N... with the Famicom's 2SA.
(http://www.gnys.se/da_bear/famicom/DSC_9250.jpg)
Be aware that doing this will permanently disable RF output from your Famicom!
Great pictures, thanks for sharing! I will definitely try it!
Did some more testing today.
Tried several caps over the PPU without any luck reducing the vertical lines.
BUT! I had the machine laying upside down with the gut open towards me, and for some reason I tried lifting the wire running from #21 off the board, and the lines became almost completely invisible!
So, I extended my wire (the green one in the pictures) and placed it next to the board instead of running it straight over.
I also resoldered it to pin #21 making it point up more. Success!
In SMB1 I only see something that looks like lines when I'm in the swimming levels. In SMB3 you can see them if you really want to.
Right now, I can't think of anything more you can do besides using a shielded cable instead.
There is interference from both the PPU, CPU and connector traces that the wire can pick up. So avoid them as much as possible and secure the video wire with some heat glue.
Excellent Da Bear.
I have done a few of these mods but will give it a try using your method.
One thing I noticed. You cut the track from Pin21 but from what I can see once you remove the 2SA937 that track foes nowhere. Do you need to cut this trace?
Looking at the top picture you can see that it goes nowhere. i could be wrong.
I am finding that the picture is not as bright as it could be. Is there any way of boosting the picture quality on this one? On my 80cm TV it looks a bit dull. On my 51cm TV it looks pretty good.
I will try this on the next console and compare the results.
I tried Da Bear's method on my top loader and it's definitely an improvement over kyuusaku's original circuit. The video quality is slightly better than with the 2N3906, though I'm still getting the vertical lines. However, the lines aren't as visible as they were with kyuusaku's circuit. Although instead of cutting the trace to pin 21, I lifted the pin so that it would be completely isolated from the motherboard.
Glad to know it's working!
It's probably not neccessary to cut the trace if you lift pin #21 from the board and run the wire on top of the board.
But if you don't lift #21 And don't cut the trace, it will pick upp interference from the traces that runs below thus giving vertical lines. Think of the remaining trace as an antenna.
A shielded cable running as far away from the board as possible is the last thing to do to eliminate contamination of the video signal.
Are you sure the brightness setting on the TV is correct? I have 3 TV sets that I have tested my FC on and it looks great on any of them.
1 Samsung 32" Wide CRT
1 Panasonic 32" Wide CRT
1 LG 50" Plasma
Sample picture taken on my Plasma:
(http://www.gnys.se/da_bear/famicom/DSC_9264.jpg)
Post Merge: October 01, 2011, 02:13:29 pm
Today I changed my green videosignal cable to a shielded cable. I grounded the cable shield at PPU #20 and at the collector of the transistor.
The result is 99% perfect picture. :pow: I think this is the best it can get without rewiring the PPU completely, and I'm not going to do that! :crazy:
This is what I have done to my poor ::) Famicom
* Buildt kyuusaku's video curcuit using the famicom 2SA937 transistor. It's located near the PPU and is marked as Q1.
* Desolder Q1 and cut the trace from PPU #21 to Q1. Cut it in both ends as close to #21 and Q1 as possible. (If you don't want to cut in your board, you need to lift pin #21 from the board isolating it.)
* Used a shielded cable that I grounded to PPU #20 and the collector of the transistor.
* I have placed the video circuit at the RF box (Next to it, not inside :) ) as there is the most space there. Just keep in mind that you need to run your shielded cable around the board and not straight over it to minimize contamination of the video signal.
* And to finish it of, I have secured my wiring and my circuit with hot glue.
I have done this on a 02F board and I'm gonna try it on some older ones to so stay tuned for that :bub:
I also redid the AV mod on my Famicom with this method and it didn't reduce the vertical lines one bit. I got better quality video like with my top loader, but I'm still getting jailbars. Unlike my top loader, I did what Da Bear did and cut the trace going from the PPU video pin to the 2SA937, and I also used shielded cable for the line going from the PPU to the base pin.
Did you desolder 2SA937? Where have you placed the new circuit?
If you can, take a picture of the board and one of your TV with the game running.
Quote from: Da Bear on October 03, 2011, 01:33:03 pm
Did you desolder 2SA937? Where have you placed the new circuit?
If you can, take a picture of the board and one of your TV with the game running.
I desoldered the 2SA937 from the motherboard just like I did with my top loader. Right now I've got the circuit wedged in the gap between the RF modulator board (which no longer has the RF modulator) and the motherboard. I'll see about getting pics for you later this week as I'm busy for most of the week.
if you cut and up carefuly the leg 21 and solder of top separate to the motherboard, reduced the jailbars to minimun
Quote from: cmv2 on October 10, 2011, 02:03:17 pm
if you cut and up carefully the leg 21 and solder of top separate to the motherboard, reduced the jailbars to minimun
Yeah but if you break the leg (highly possible!), you can throw your PPU to garbage... just a warning.
almost everything can be fixed
example
http://www.elotrolado.net/hilo_tutorial-reparar-patas-del-chip-snes_1633122
Haha brutal force applied! :D Nice!
But be real, not everybody can do such a thing... and by using a drill/ angle grinder to remove part of the chip, everything can happen. It may also cause too much heat so it destroys the chip by overheating it.
I only said it if you want to avoid jailbars, if someone had better lower their own risk
I have a theory I would like to share.
Right now I'm av modding several Famicoms and it works out just fine doing the way I have described. ie cutting traces and moving Q1.
But one machine didn't respond to my mod. Heavy jailbars and a buzzing sound coming out the speakers of my TV.
I measured the voltage regulator and I only got ~4.8v from it. The ones that don't give me vertical lines are those who have ~4.9- 5.1v from the voltage regulator.
If you want to measure the voltage and reply here how much it outputs and how bad your lines are I would be happy. I suspect that underpowered boards gives more interference.
Nice find, when I get to it I will measure my current modded Famicom and report here. Also, what revision board are you talking about (the one with heavy jailbars)?
When I find myself some time, I can also try to exchange the "classic" 7805 with one of local manufacturer alternatives, just to see the diference.
http://www.iowaind.com/Manufacturing-Equipment-/Lathes-/Needing-Repair-/New-MA7805-tesla-ic-MC7805CK-7805-photo_example.jpg
The one that has got bad lines is a HVC-CPU-GPM-02.
The other GPM-02's I tried this on works great, also does the HVC-CPU-07 boards. The older boards have slightly more visible jailbars then the newer ones.
But this faulty GPM-02 is the worst I have seen so far.
I'll try to change the voltage regulator with one I know is giving proper voltage to see what happends. Could be some other component that's faulty to. Don't know yet.
Post Merge: October 25, 2011, 09:10:46 am
Anyone knows if the components in the Famicom would handle 6v? If so I could try to change 7805 to a 7806 to se if more power means less jailbars.
Quote from: Da Bear on October 25, 2011, 12:58:08 am
I have a theory I would like to share.
Right now I'm av modding several Famicoms and it works out just fine doing the way I have described. ie cutting traces and moving Q1.
But one machine didn't respond to my mod. Heavy jailbars and a buzzing sound coming out the speakers of my TV.
I measured the voltage regulator and I only got ~4.8v from it. The ones that don't give me vertical lines are those who have ~4.9- 5.1v from the voltage regulator.
If you want to measure the voltage and reply here how much it outputs and how bad your lines are I would be happy. I suspect that underpowered boards gives more interference.
Hey Da bear,
I have a model that is doing the same thing. One thing I did find is that the buzzing would totally disappear when controller 2 was not attached. As soon as it was attached it came back. I know it was not the controller as I have a few spares and they all did it. Try this and let me know if the buzzing goes away.
I had the same problem with the annoying buzzing and I found a fix for mine.
Just open up the player 2 controller and solder a wire just like in my pic.
(http://i4.photobucket.com/albums/y101/pikkonson/th_DSC_0227.jpg) (http://s4.photobucket.com/albums/y101/pikkonson/?action=view¤t=DSC_0227.jpg)
Once I did this the buzzing went away and the controller and the mic work fine.
Quote from: Da Bear on October 25, 2011, 02:19:24 am
Anyone knows if the components in the Famicom would handle 6v?
I believe it will. That increase is insignificant. I have famiclones that run on 9V without any voltage regulator (they run fine on 5V too).
I have measured my current modded FC, but I haven't desoldered the original transistor. It had strong jailbars so I attached the capacitor on the PPU and they dissapeared. The voltage on 7805 is 5,01 - 5,02V. My setup (it's HVC-CPU-GPM-02C) (https://picasaweb.google.com/104600295437428529732/Fcmod?authkey=Gv1sRgCKOKlZ6Xxt3nfw)
Quote from: Pikkon on October 25, 2011, 07:34:30 pm
I had the same problem with the annoying buzzing and I found a fix for mine.
Just open up the player 2 controller and solder a wire just like in my pic.
(http://i4.photobucket.com/albums/y101/pikkonson/th_DSC_0227.jpg) (http://s4.photobucket.com/albums/y101/pikkonson/?action=view¤t=DSC_0227.jpg)
Once I did this the buzzing went away and the controller and the mic work fine.
Thanks for that one!! Something to think about. I actually think I Flucked that console right up trying to work out what was happening. Just shows a blue screen now
Quote from: cmv2 on October 10, 2011, 02:03:17 pm
if you cut and up carefuly the leg 21 and solder of top separate to the motherboard, reduced the jailbars to minimun
I just did this to my Fami today and it didn't change anything. I'll see if I can get a reading from the voltage regulator when I can and maybe replace it with a new 7805.
Quote from: mamejay on October 25, 2011, 06:57:01 pm
Hey Da bear,
I have a model that is doing the same thing. One thing I did find is that the buzzing would totally disappear when controller 2 was not attached. As soon as it was attached it came back. I know it was not the controller as I have a few spares and they all did it. Try this and let me know if the buzzing goes away.
The problem is not in the controllers since I have not had them attached at all to this board.
Quote from: jpx72 on October 25, 2011, 09:52:45 pm
I believe it will. That increase is insignificant. I have famiclones that run on 9V without any voltage regulator (they run fine on 5V too).
I have measured my current modded FC, but I haven't desoldered the original transistor. It had strong jailbars so I attached the capacitor on the PPU and they dissapeared. The voltage on 7805 is 5,01 - 5,02V. My setup (it's HVC-CPU-GPM-02C) (https://picasaweb.google.com/104600295437428529732/Fcmod?authkey=Gv1sRgCKOKlZ6Xxt3nfw)
I'm gonna try change the voltage regulator to one I know gives 5v+ to see if it makes any difference.
I also read something about building a filter between PPU pin #22 and the Xtal here: http://www.famicomworld.com/forum/index.php?topic=3093.0
Anyone know how this filter looks like and how to properly connect it?
Edit: I see that you are using shielded cables but you havn't connected the shield to ground. Am I right?
Hmm this is what "NTSC 2C02 technical reference" by Brad Taylor says about pin 22:
/SYNC: this signal when zero, will force the status of colorburst control,
scanline and pixel counters/flip-flops used inside the PPU to definite
states. Generally, this is the means of which two 2C02s connected together
in a master-slave config (via the EXT bus) can syncronize together; the
master PPU's /VBL line feeds the vblank information to the slave's /SYNC
input. On Famicom consoles, this pin is always tied to logical one. On the
NES however, this pin is tied in with the 2A03's reset input, and as a
result, the picture is always disabled while the reset switch is held in on
an NES.
I am not reading there anything about any filter amp...
I couldn't figure out the circuit around pin 22 on NES from the available NES schematics (too blurry)...but probably it's connected together with CPU pin 3 (RST) and then connects after CIC near the reset switch...
EDIT: It may be a lone shot but if pin 22 is connected to logical 1, then you can try to desolder it from the PCB and insert a 0,57 - 1k resistor between the pin and VCC. Maybe one small capacitor between the pin and GND too...
I have now replaced the 1000uF capacitor, voltage regulator and xtal. No difference in jail bars, back to square one I guess :(
But the buzzing noise dissapeared when i changed the voltage regulator, always something.
Okey guys!
Some more discoveries on pin #22!
I found this site yesterday. The mod is just about the same as the one where using here with the exception of a capacitor between PPU #22 and GND (PPU #20)
http://translate.google.se/translate?sl=de&tl=en&js=n&prev=_t&hl=sv&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fplayoffline.wordpress.com%2Fmod%2Foldfcfba%2F
I had another Famicom that gave bad lines so I soldered a 100uF capacitor (did't have 47uF as above site suggested) over #22 and #20 and the lines became very very faint with a crappy built AV board. They tend to get even fainter when I get them fully assembled.
Please note that I'm still NOT using ANY capacitor over +5v and GND.
Just mind the polarity of the capacitor!
(http://www.gnys.se/da_bear/famicom/20111103_112852.jpg)
Yes, I've removed the trace from #21 to Q1 completely. :bub:
Post Merge: November 03, 2011, 05:34:09 am
Oh...forgot to mention this.
If you hear a buzzing noise from the speakers and it's not the mic in controller 2 thats faulty it's probably the power switch that have bad/dirty contacts inside. Jerk it back and forth to clean the oxide inside and the noise should disappear.
Post Merge: November 03, 2011, 08:15:32 am
Updat on the capacitor between #22 and #20.
I managed to find one 47uF and I soldered it into my Famicom that gave very very faint lines (very hard to see) and now I can not see any lines at all from that machine. None!
I have tested this on 2 machines now, one with very bad lines, and one with very faint lines.
The "bad" machine with capacitor now gives as faint lines as the good machine without capacitor. The good machine with capacitor = no lines!
jpx72: Maybe time to update your guide on your homepage? ;)
Nice discovery, I'm going to try that on my Famicom and see if it helps. Maybe I'll even try it on my top loader and see if I can get line-free video out of it.
Quote from: Da Bear on November 03, 2011, 03:40:57 am
I managed to find one 47uF and I soldered it into my Famicom that gave very very faint lines (very hard to see) and now I can not see any lines at all from that machine. None!
jpx72: Maybe time to update your guide on your homepage? ;)
Hey very nice!
I would still be curious to know the results of desoldering the RST pin (#22) and inserting the resistor there, in combination with the capacitor you've placed there too. This:
(http://img822.imageshack.us/img822/869/ppux.png)
This way it would be pretty close to a NES ciruitry.
Maybe you can try it on the "bad" machiine, just be carefull not to break the pin22.
Tried the capacitor on both my Famicom and NES top loader as well as a top loader I modded for someone on Sega-16. I can't say it's completely eliminated the lines, but it has reduced them significantly, especially on the top loaders.
Quote from: jpx72 on October 25, 2011, 09:52:45 pm
My setup (it's HVC-CPU-GPM-02C) (https://picasaweb.google.com/104600295437428529732/Fcmod?authkey=Gv1sRgCKOKlZ6Xxt3nfw)
Quote from: Da Bear on October 26, 2011, 02:48:24 am
Edit: I see that you are using shielded cables but you haven't connected the shield to ground. Am I right?
Forgot to answer you on this - the shielding is grounded, it's just not visible on the photo. Also the R110 and C220u are not visible there, because I soldered them near the cinches (on the other side of the cable that goes from my famicom).
2A03 - thanks for the feedback! I will definitely try it too!
I'll make a try with the resistor.
Post Merge: November 04, 2011, 05:25:36 am
So, I lifted pin 22 from the board and soldered the resistor between the pin and +5v and the capacitor between GND and pin 22.
Result: The lines came back :bomb:
Refitted the pin and my capacitor and the lines became faint again.
Thank you for the test! Oh isn't that great when somebody helps with testing ideas?
:star:
So this is not the right way... Ok, I'll post my results when I test the #22-47uF-#20 on my setup. Will try both with #20-1000uF-#40 and without it.
All here make's a great modding team. Knowledge is nothing if you can't share it :)
When you are on it, try caps from 47uF to 220uF on #22-#20. I don't think it makes any difference with bigger cap, but who knows. :D
Quote from: 2A03 on November 03, 2011, 11:55:02 pm
Tried the capacitor on both my Famicom and NES top loader as well as a top loader I modded for someone on Sega-16. I can't say it's completely eliminated the lines, but it has reduced them significantly, especially on the top loaders.
That right there is a break-thru! I would love my NES Toploader to have that mod for sure!
As I recall, part of my research pointed to the lines being caused by the signals of PPU Pin 25 (A13) becoming commingled with the ground plane. If you draw a video signal directly from A13 (may have been Aq2), you will notice vertical bars that overlay exactly where the stripes fall. This video contamination is what I was, and am (when I get back to it) working to rectify.
To test this, wire your A/V board to everything but the video signal, and connect the lead from your amplifier (that normally goes to 2C02-p.21 'Video') to 2C02-p.25 'A13' and look at the video display from that signal. Compare it to the position of the lines, and you will see exactly what I mean in vivid detail. The A13 signal travels very close to GND in several places, so re-routing it is possible, but extensive.
(I didn't go that route, although I played with the idea, as it is not ideal. You'd need to life the traces and use shielded jumpers to connect the paths by hand in order to change it. I'm exploring other options...)
You may want to play around with this information... Use it as you see fit: Perhaps you will find it useful, as the best way to fix this problem is to circumvent the cause, not merely deal with the symptoms. :bomb:
Quote from: The Uninvited Gremlin on November 05, 2011, 08:53:56 am
Quote from: 2A03 on November 03, 2011, 11:55:02 pm
Tried the capacitor on both my Famicom and NES top loader as well as a top loader I modded for someone on Sega-16. I can't say it's completely eliminated the lines, but it has reduced them significantly, especially on the top loaders.
That right there is a break-thru! I would love my NES Toploader to have that mod for sure!
That can be arranged if you'd like... ;)
Xious> thanks, I remember you (or somebody here) already pointed that A13 thing here, but I haven't put much attention to it... How's the situation with the A13 on US NES by the way?
Da Bear> I have tested a couple of things on my setup, but the result wasn't very different. By connecting 47uF or 100uF between #20and#22, the lines were barelly visible, which is ok, but it was exactly the same result as when I had connected the 1000uF on #20 and #40. I even made a couple of photos (https://picasaweb.google.com/104600295437428529732/Jailbars?authkey=Gv1sRgCMma3v7_6NDjpQE), but there's not much to see (I have my video capture setup currently disassembled).
I don't recall if there was anything different on the NES (front-loading type). I think there is less interference from this line, but I didn't meddle too much with the NES layout. I figured that anything I design that would rectify this problem on a Famicom would be a universal solution.
One of my mates, who's an expect int he field of analgoue video was going to examine it with me, but he's been busy working 80+-hour weeks for the last several months, so we haven't yet sat down to closely inspect this problem. I do have some other areas that I will be examining this winter as well. :bomb:
Quote from: Pikkon on October 25, 2011, 07:34:30 pm
I had the same problem with the annoying buzzing and I found a fix for mine.
Just open up the player 2 controller and solder a wire just like in my pic.
(http://i4.photobucket.com/albums/y101/pikkonson/th_DSC_0227.jpg) (http://s4.photobucket.com/albums/y101/pikkonson/?action=view¤t=DSC_0227.jpg)
Once I did this the buzzing went away and the controller and the mic work fine.
Hey Pikkon,
Just did an AV mod and had the buzzing audio. Did you wire mod and it perfect now!!
Thanks for that!
Just on the AV mod. I have done a few and the results are pretty good. I just got a famiclone and the colours and brightness are so much better. Is there a way to boast the video signal by modifying the amp in someway?
Quote from: mamejay on November 08, 2011, 03:15:34 am
Just on the AV mod. I have done a few and the results are pretty good. I just got a famiclone and the colours and brightness are so much better. Is there a way to boast the video signal by modifying the amp in someway?
Boost the signal on a Famicom or Famiclone?
On the Famicom I recommend you to reuse the Q1 transistor found next to the PPU for best colors och sharpness. It would probably work just as good in a Famiclone but I have never tried it.
Quote from: Da Bear on November 08, 2011, 04:52:03 am
Quote from: mamejay on November 08, 2011, 03:15:34 am
Just on the AV mod. I have done a few and the results are pretty good. I just got a famiclone and the colours and brightness are so much better. Is there a way to boast the video signal by modifying the amp in someway?
Boost the signal on a Famicom or Famiclone?
On the Famicom I recommend you to reuse the Q1 transistor found next to the PPU for best colors och sharpness. It would probably work just as good in a Famiclone but I have never tried it.
Sorry I meant the Famicom. The famiclone has AV out standard and looks so much better that the AV modded Famicom. On the next one I will try using the Q1 transistor.
Anyone thought of using a PNP transistor like when building an AMP for the Sega Master system and Megadrive S-video outputs.
Would just be video in on the base and then a 75ohm resistor on the emitter to video out
Don't thinks it's so easy on the Famicom since it only outputs composite. The Megadrive/Genesis have a much more sofisticated video chip that outputs both RGB and composite. And as far as I understand, you don't tap the composite signal when doing an s-video mod on the Sega. Instead you use the Chrominance/Luminance output.
I have found another modding attemp - this one requires desoldering the PPU and placing it on a separate board:
http://www2s.biglobe.ne.jp/~tns/hvc2/
(http://img265.imageshack.us/img265/5168/hvc2t2a2.jpg)
NICE!
Quote from: Da Bear on November 08, 2011, 09:31:16 pm
The Megadrive/Genesis have a much more sofisticated video chip that outputs both RGB and composite.
Technically the Genesis/MD VDP outputs RGB, which then goes to a video encoder chip that outputs analog RGB in addition to composite and S-video.
Hi. I do av mod, but i'm have a problem. Look upside picture. Help me fix it.
(http://savepic.su/886802m.jpg) (http://savepic.su/886802.htm)
Please provide photos of your actual modification, as well as a list of the parts that you used, if you want any actual (and helpful) answers...
Did you do this on a Famicom, or on a Dendy? :bomb:
Dendy :D
No. Dendy have AV. Dendy is shit.
PCB HVC-CPU-GPM-02
http://www.h3.dion.ne.jp/~kuboken/famicom/famav2.html
(http://savepic.su/902178m.jpg) (http://savepic.su/902178.htm)
Well one thing is that you should try to put the components around pin #21 of PPU and not on the place where you have it.
Second, put a 47uF capacitor between pins #22 and #20 or 1000uF between #20-#40
Third, use shielded cables.
Fourth, try another mod (http://jpx72.detailne.sk/modd_files/fc/avmod/kyuusaku.gif), with PNP transistor.
Fifth: READ the whole topic, you won't have to ask questions like that anymore! :P
What kind of transistors have best picture quality?
I presume your worried about the distortion in the image, such as I see in the status bar there?
The NPN modification works just fine; I prefer a different transistor over the 1815 personally, but this will be alright. The methodology is not that great, as directly soldering the components like this always leads to potential problems.
I note that you did not use an electrolytic capacitor (condenser), which is against protocol. I suggest a 1µF electrolytic cap in place of your .47µF ceramic capacitor, with the negative axial connected to 'Video In' and the positive axial to your collector, and the 22kΩ resistor that bridges it to the +5VCD source .
You also need to tie your emitter to your video out connection via a 75Ω resistor; this will couple to the 220Ω resistor that is also connected between the emitter and GND/CE.
Finally, I advise removing this entirely and using a small piece of Vero board to assemble the components, then attach them to the correct points on the FC logic board with standard jumper wire, or shielded wire (at your discretion).
I also sell (assembled and parts-only) RetroVideo A/V kits, and (do-it-yourself) PCBs for A/V modification here (http://www.atariusa.com/RetroVideo). :bomb:
Thnx for answer me.
What kind of PNP transistors have best picture quality?
If you don't mind desoldering the transistor 2SA937 originally used in the Famicom you should use that one. It's marked Q1 on the motherboard and placed next to the PPU.
That one can't answer, as the truth is non-conclusive. I personally think that a few NPN transistors have the best quality; others swear by PNP. The reality is that it is very subjective, and that ultimately, 'best quality' is based on too many factors, especially personal opinion. In truth, for this type of application, NPN and PNP are essentially identical.
PNP and NPN don't in and of themselves make any prominent difference; the actual frequency ranges, and the waveforms involved differ between different models and materials, but I won't say that the physical charge makes a difference, aside from how it's implemented / integrated (e.g. direction of flow).
You can buy a selection of RF video amps and see which you prefer. In fact, you could build it around a 12BY7 vacuum tube (as I'm considering doing for my own amusement) if you desire...
For now, you need to correct the flaws in your existing installation. before worrying about transistor types. :bomb:
P.S. I thought that the first (and most early) Dendy models were RF only, PAL units... Essentially complete clones of the Taiwan Famicom, of very close; maybe like the FC with a Makko kit. I'll need to look at that again.
P.P.S. I honestly don't see the appeal either of desoldering the '937 or of reusing it. Additionally, you will most certainly need to re-wire the entire modification if you do. Simply removing Q1 will cut the feed of video to the RF modulator, and thus to the video bridge, which is where you have connected your existing modification. I think that if you fix the problems as I outlined before, you will be fine...
You never did clarify if your video problem was the distortion (wavy lines), like the status / life bar area on your photo, or if it is something else you are seeing.
Hi everyone, i tried this mod today, and got decent results with a couple problems as follow
The major problem is a green bar around the middle of the screen, getting some ghost effect from graphics around the right side of the screen:
http://www.youtube.com/watch?v=Dvt6pUehv-s
EDIT:
Made another vid where its more visible
http://www.youtube.com/watch?v=er7f5IydKbo
And of course i have the vertical bars, tried using a 470uf and 1000uf capacitors betwen 40# and 20#, with no results, and a 100uf betwen 22# and #40, nothing too:
http://www.youtube.com/watch?v=0W__hI1oG28&
They are far more visible than show in the video due all the reflection on the TV
The bars doenst bother me much at the moment, you can only see then in games with light colors like Kirby and Mario. That green bar in the middle appears only when theres a black backgroung.
For one did you try your famicom on a crt tv instead of a flatscreen.
So , is there anyone suscessfully modded their system vertical line - free with out problem? CAn you please write the instruction for your mod.
Quote from: Zombar on December 02, 2011, 03:28:01 am
Dendy :D
No. Dendy have AV. Dendy is shit.
why did you think so?
original 'dendy classic' have both AV and RF outputs and provide clear lineless picture on the AV. No annoying jailbars!
Main dendy's disadvantage is PAL system which plays game more slower than on NTSC system due to another framerate.
Post Merge: January 18, 2012, 10:39:19 am
Quote from: Zombar on December 02, 2011, 05:31:00 am
What kind of PNP transistors have best picture quality?
by the way, the cheap general purpose low-power low-voltage transistors were used in famicom video circuit. And they work like a charm!
personally, i use for AV-modding kt3102 and kt3107 - they had similar functional characteristics. And they are cheap, too!
if you want to use better transistors just try to find out similar transistors with the lower noise output level then original one have.
just adding 2 cents from my own av-modding experience.
i've used video amp circuit from famous Dendy famiclone, because it has correct brightness and color signal level.
only shielded cables were used and Q1 (2SA937) were desoldered from the PCB.
initialy, the circuit were connected directly to PPU 21st pin and image still contains recognizable vertical lines.
but after video_out pin were lifted out from the PCB, the lines had become more unnoticeable, then before.
all pictures are attached.
Could someone who has done this recently do me a huge favor and please post *exactly* what parts they used (and where they got them if at all possible)? With the details given on the guide, when I go to look for the transistor, resistors, and capacitors, the number of different options are mind-boggling. Perhaps those other details don't matter, but I'd rather use *exactly* the same parts as someone else who has successfully done this, if you know what I mean. :)
Many thanks!!
This is what I use when I AV mod Famicom
1 x 300 ohm resistor
1 x 110 ohm resistor
1 x 220uF capacitor
1x 2SA937 transistor from the Famicom (Q1)
Optionally add an extra 220 uF capacitor that you solder between PPU pin #22 and #20 to reduce some jail bars. I also remove the trace between PPU pin #21 and Q1.
For my HVC-GMP-02C I am using these for the video part:
BC 178 - PNP tranzistor
330 ohm resistor (couldn't find 300)
120 ohm resistor
220 ohm capacitor (for 16V)
For the jailbars:
470 uF between PPU pins #20 and #40. Trace between PPU pin #21 and Q1 NOT removed, not even cut.
For the audio output I have added a 47 uF (10V) capacitor:
output o-------- -[47uF]+ ------o Famicom
Everything bought in local electro shop. I'm used to services there, those guys can always help and give possible alternatives.
mine is hvc-cpu-07 rev.07 bоard
1) Q1 is desoldered,
2) PPU pin #21 is lifted out of the PCB
3) 1500uF aluminium electrolytic capacitor + 0.1uF ceramic capacitor between PPU power pins.
part:
1) 1 x KT3107E - PNP transistor (replace parts are BC 212, BC 556, 2SA970, 2SA1049, and others)
2) 1 x KT3102E - NPN complementary transistor for KT3102E
3) 2 x 220 Ohm resistor
4) 1 x 2200 Ohm resistor
5) 1 x 75 Ohm resistor
6) shielded signal cables
this circuit drives 75 Ohm output load that is more preferable for all tv sets.
audio is connected directly to the #46 cartridge pin.
About the audio output - when connected directly to #46 cartridge pin, by connecting this output to audio card of a PC, there is only buzzing sound. So adding the sound output capacitor is a good idea.
most of the audio capture devices have capacitors on the inputs, unless you are using extreme professional hi-fi systems ^_^
Quote from: jpx72 on February 12, 2012, 05:14:59 am
So adding the sound output capacitor is a good idea.
yes, the idea is good. This capacitor is used only for removing the DC current from signal.
i dunno how it can remove buzzing sound, because any sound that you hear contains only the AC waveforms.
http://ompldr.org/vY3M0cQ/btdd_fc.ogg here my sample. Normal FC sound with little interference from video signals.
Quote from: famifan on February 12, 2012, 07:09:44 am
i dunno how it can remove buzzing sound, because any sound that you here contains only the AC waveforms.
I am not talking about low buzzing sound in the background, but completely buzzed output (not hearing any melody). Maybe it's not affecting all sound cards, but probably all on-board ones. Sometimes it's needed to electrically (galvanically) separate two electrical components (in this situation Famicom and PC card), and that can be done with adding a capacitor between them (to compensate two different ground potentials).
I just bought a famicom from EBAY & tried several mods with no luck :'(. It is a model: HVC-001, board revision: HVC-CPU-07 (1984, but mine has the 1983 RF modulator?), serial # H7766073. I am currently trying kyuusaku's mod because Da Bear is using it & it looks as he has the same model Famicom as me. Before I did anything I hooked it to a NTSC tv (several LDCs then then tried later on CRT) via RF on cable channel U.S.A. 95 & 96). picture & sound come in fine on all TVs i tried (albeit picture is fuzzy & has interference, but my RF RCA plug is tarnished). Then when I tried my 1st mod, i can get a (faint) picture, but it is not stable, skewed, and wrong colors. from my EE experience it looks like a different tv system or wrong Hz, but i got it working using RF & model# seems correct U.S.A. & I purchased it from a Japanese ebay seller (not HK). I do have a computer monitor that will do PAL, but it will tell me with the on screen display which tv system it uses if it switches to PAL (which it doesn't). I tried different spots on pcb to tap video (& ran it direct from pin21 to RCA in on TV), isolated pin 21 & removed OEM transistor (2SA937). i tried different spots for ground & separated spots to ground video shield & mod transistor ground. i tried various mods; using pnp/npn variations. even doing these things, i still get roughly the same signal, just different degrees of distortion & interference of the video signal. I'm almost at the end of my "wits' end" & don't want to buy a kit if i'm just making a simple mistake or am just ignorant of some obscure knowledge about the particular famicom I'm using. I am also worried if i do buy a kit & still have bad luck. one other thing i noticed is I'm using a generic PSU made for USA NES it outputs 9vdc (unlike the OEM ac/ac PSU) @ 850ma. I also used the SEGA Genesis (1st gen, model MK-1602) AC adapter (9vdc, 1.2A). but my meter only gives 4.8v on the voltage regulator. So I replaced the 7805 regulator (Radio Shack# 276-1770) & it now reads 5.0vdc, but did noting at all to improve picture (in fact, i saw no change at all). I also heard problems with U.S.A. being 110vac & japan being 100vac. But I think i eliminated this problem by using a U.S.A. ac/dc (rectified) transformer & new regulator it shouldn't matter, correct? Seems like as long as I'm still getting a clean 5v on the board it shouldn't interfere? I also noticed the PPU (RP2C02E) & CPU (RP2A03-E) is the same as a U.S.A. NES I have laying around for parts. I am considering swapping them (PPU first), & see how both systems are affected. My parts NES is already socketed from the time when I was about to add a "Copy Nes" from RetroZone. If that doesn't help, I'm at a loss. I might also try replacing the caps on the voltage regulator circuit & any that are inline with ground-->VCC and ground-->video. I know the Famicom works, so If this problem just becomes an unexplained mystery, I will just restore the OEM RF & make due. I specialize in mostly digital electronics, so video is somewhat new to me. I would appreciate any experienced advice or info anyone could give me. [I'll add pictures as necessary]
Quote from: Xious on November 05, 2011, 12:46:58 pm
As I recall, part of my research pointed to the lines being caused by the signals of PPU Pin 25 (A13) becoming commingled with the ground plane. If you draw a video signal directly from A13 (may have been Aq2), you will notice vertical bars that overlay exactly where the stripes fall. This video contamination is what I was, and am (when I get back to it) working to rectify.
To test this, wire your A/V board to everything but the video signal, and connect the lead from your amplifier (that normally goes to 2C02-p.21 'Video') to 2C02-p.25 'A13' and look at the video display from that signal. Compare it to the position of the lines, and you will see exactly what I mean in vivid detail. The A13 signal travels very close to GND in several places, so re-routing it is possible, but extensive.
(I didn't go that route, although I played with the idea, as it is not ideal. You'd need to life the traces and use shielded jumpers to connect the paths by hand in order to change it. I'm exploring other options...)
You may want to play around with this information... Use it as you see fit: Perhaps you will find it useful, as the best way to fix this problem is to circumvent the cause, not merely deal with the symptoms. :bomb:
How could I miss this post?
This weekend I'm borrowing a oscillioscope and I'm going to take a deeper look into this. :)
More discoveries, no answers :'(
So, I swapped the my Famicom PPU with the NES PPU, no change. I also completely desoldered the RF board completely & replaced with a breadboard power supply (regulated by a 7805, 5vdc). again, no difference in picture. the trouble has to be the mod or something else on the motherboard (possibly bad caps?). One thing i had in mind was to add a RF modulator from another U.S.A. game system (PSX, DC, GENS2, N64, ...etc) to the Famicom board. At least that way, I can still play on CH 3/4 without the interference I get from the NTSC-J CH 95,96. I'm still trying to come up with any ideas what to do.
here's my mod:
(http://IMG1252.jpg)
this is what I get:
(http://IMG130.jpg)
here's my board:
(http://IMG135.jpg)
@ bitmerge6502
Everything you said seems fine, there really shouldn't be any problem with your output. But there is. So I suspect the transistor. Can you replace it for something else?
Changing PPUs didn't made any difference so stick with the original one for the time being.
Try to connect PPU pin 21 directly to your TV without any components between them, you should get the signal too, it may be discolored but shouldn't be distorted (don't forget to connect GND). Let us know the result.
You can also play with the variable resistor on the Famicom PCB that is near the xtal. Mark the original position with a marker and turn it a bit, maybe you can get something from that.
Also try to change the 470uF cap for a 220uF one.
One step at a time, test in-between.
Double check if those resistors are really the ohmage you've written. Or try to replace them. This whole problem seems a "AV MOD" problem, not the Famicom's problem.
About the power input, as you said, you have 5V on the 7805 output so that's fine.
I'm not sure if it does any difference but try change the place of the resistor and capacitor. And doublecheck the values of the resistors.
Post Merge: February 24, 2012, 06:48:43 am
It could also be a problem with the capacitor. I remeber when I accidently scraped of the insulation of the capacitor and it touched ground, and had similar distortion in the picture. Took a while to figure out what was wrong. :D
i used several types of transistors & pnp/ npn combos. i also completely bypass the mod & connect video strait to pin21 (in fact, i do this everytime i make a change). the x-tal is the same as my nes (21.4772). so i'll mess with the timing circuit (check caps first) after i try to get something out of an usa rf modulator.
bitmerge6502, your famicom video distorsion is caused by non 75 Ohm output driver.
you can use my schematic from previous page, it is completely 75-Ohm driver.
Post Merge: February 24, 2012, 09:47:22 am
Quote from: jpx72 on February 24, 2012, 02:38:13 am
Try to connect PPU pin 21 directly to your TV without any components between them, you should get the signal too, it may be discolored but shouldn't be distorted (don't forget to connect GND). Let us know the result.
if you connect the open collector pin directly to 75 Ohm load like your TV AV-input you will get nothing. Signal level will be too low, right above the zero level.
thanks! i'll try it when i get home tonight. i also been thinking about using a 4050 buffer inline with the video input & pin 21, or in place of the transistor altogether.
Post Merge: February 24, 2012, 08:33:21 pm
I have a bunch of these generic RF boxes laying around, so I soldered one directly to PPU PIN# 21. And... It works (minus the "jail-bars")! This means the signal coming from the Famicom board (at least ay pin 21, which I isolated anyway) is compatible with my TV (& others) & clock timing is correct. So I basically troubleshooted it down to the mod itself. This is what baffles me, because I tried several different mods from this forum & other websites. Mostly I have been working off a breadboard (except for the one int my previous picture). Some of the transistors I tried (mostly from my available supply) are: PNP = PN2907, 2N4403, MPSA77, MPSA70, 2M700, & the Famicom's A973P. NPN= 2N2222, 2N3904, 2N4401. It would seem one of these mods would work. I'm almost sure there's some small detail I'm overlooking. I have yet to experiment with matching the load to 75ohm TV input. I'm not completely sure how to test on the meter what the signal load is. I know video signal strength is measured in decibels (like a cable TV signal meter). I'm going to try famifan's mod & try to keep the lead wires as short as possible & solder them "component to component" rather than use the breadboard.
Post Merge: February 24, 2012, 10:42:48 pm
Post Merge: February 24, 2012, 10:43:14 pm
:)GOTIT! :)
I rebuilt the mod using 1/8 watt resistor & got all the components as close together as I could. Then I added a 75ohmR between the cap & video out RCA. fired it up &... I got a really clean signal! the jail-bars are still there, but faint (or at least much fainter than the OEM NES top loader or YOBO or GEN NEX clones). The only problem: The picture rolls :(.
but then (on a hunch) I swapped the 220 uF cap for a different one (of the same type). The picture stopped rolling & was due to a bad capacitor (that what i get for salvaging & trashpicking my components :-[ ).
Well thanks everyone for your help! I have some more mod ideas I'll be posting soon along with a link to my restoration page when it's up. I'm glad I found this forum community. I always wanted a famicom since I first seen one in a magazine as a kid, now I can actually play & enjoy mine.
This may be irrelevant, but I remember having problems with the picture too and the problem was in the AV cable that I used to connect the FC to TV. It had a 75ohmR hard-built inside the cinch connector. It was a AV cable from european NES.
AAAANYWAY congratulations! Have many hours of FAMI FUN!
Had some fun this weekend ;D
With the help of a friend we hooked up an oscilloscope and tried to locate the noice. What we found was, without a gamecart and with power to the FC all the lines where 'fine'. Minimal powernoice and a nice and steady sine wave from the xtal all the way in to both PPU and CPU.
But when we inserted a game and powered on, hell broke lose inside the motherboard. VCC went from a thin line to at least 4 times bigger. A lot of noice! The xtal sine wave duplicated, and sometimes even tripled. :o
No idea where and what is causing this (yet), but I added some (a lot of) capacitors to the board to clean up the powerline. I have not checked the signals after, but they should be much more stable since there is only some very faint vertical lines remaining.
IGNORE THE WIRES BETWEEN PPU AND THE CONNECTOR!!! Tried to rewire the lines that goes near PPU pin #21 to figure out if there was any of them that was transmitting noise to pin #21. THERE WASN'T! The noise travels out in the powerline and then contaminates everything on the board. I have NOT cut or lifted PIN #21 and I use Q1 in place to drive my AV out.
The size on the 'lyt' caps varies from 1uF to 10uF and the ceramic ones are 100pF to 100nF. And if I change all 'lyt' caps to maybe 47uF and the 100pF ones to 100nF I believe there shouldn't be much left of the vertical lines.
(http://www.gnys.se/da_bear/famicom/fccaps.jpg)
Any thoughts on this?
hice job!
i'd added ceramic capacitors on power lines of every IC too. 100nF+10nF
also, i'd retraced pin 25 (A13) as you mentioned above.
but i can't see the differences or improvements.
could you please capture the picture from "Darkiwng Duck" as i did?
We don't have that game. You should use a more common game to compare with.
okay! please choose the another common game with the bright color palette and vast one tone areas.
Hello world! :) I am a young French and I discovered this forum because I threw myself into changing my av Famicom (excuse me but I will surely make spelling mistakes ...)
I made the change with this method (http://jpx72.detailne.sk/modd_files/fc/avmod.htm), and it works very well, I find that the quality and the colors are even better than the Famicom AV official! Except the famous vertical bars ... So I tried putting capacitors between the pins of the PPU but it did not change anything ... I tried to read the pages of this topic but I did not understand everything, I thought I saw that disconnecting the pine 21 PPU directly, you can delete them?
If someone here could help me, that'd be great! :help:
Thank you! :bub:
famiav, don't worry about spelling.
do you have AV-capture hardware for PC?
if yes, could you post the pictures with noticeable vertical bars?
Quote from: famifan on March 12, 2012, 11:19:25 am
famiav, don't worry about spelling.
do you have AV-capture hardware for PC?
if yes, could you post the pictures with noticeable vertical bars?
Yes, I have one. But the video input of my hardware only accepts PAL (or SECAM French), so my screenshots will be in black and white because Famicom's av out is NTSC ... However, I have found on the Internet a picture that is exactly what appears on my TV(with the same game) :
(http://s18.postimage.org/gh5pxao55/famicomppudifference.jpg)
Can we do something? As I said, I tried to put capacitors, but no change! Thank you famifan to try to help me !
I can post some screenshots too because it looks the same and i have a way to capture them ( goot thing my capture card is usb and i can use it on my gf's laptop :D )
Ok, I hope someone will help me find a solution to remove these bars because I'm really happy with the result on my Famicom AV modded, except these bars ...
( I bought at auction on Ebay Kattetekita Marios Bros for only 13 € ($ 17.03), and play on the Original Famicom is pure happiness :) it would be even better without these bars ... )
okay FW-folks, i've captured some more pictures from SMB and RECCA.
as you can see, jailbars are sooooo faint and unnoticeable.
(ignore some horizontal blur bars caused by 60HZ horizontal sync and noise from a PC and cheapest av-capture hardware)
Any thoughts on this?
Warning: I make spelling mistakes and English ... I try to do my best!
I still have not found any effective way to eradicate these bars. But meanwhile, I'll show you MY AV modification that nobody has yet done I think: D
So I wanted to change my Famicom with an AV output, however, I am a collector, and I did not want to pierce the hull of my console to graft RCA plugs. So I wanted to get out of one of two holes in the console accessible (GAME and switch TV channel) a shielded cable with RCA plugs at the end of ... But I confess that I tried it did not!
So I had the idea of an external box that contains the console with my setup over the RCA! After numerous tests, it worked very well, I had a very beautiful image! You tell me that I could stay in there. No!
It turns out that one of my shelves, I had a SNES, which was broken long ago, and I wondered: why not use the AV Out connector for my setup in my case. Here's my idea:
http://www.hostingpics.net/viewer.php?id=732920SchmaI.png
So I desoldered the connector, I spotted the points Video, Audio and mass. So I decided to break my box and include this connector Official! However, once I plugged my cable AV Out Game Cube (which is PAL I said, I live in France I recall), the image was dark and the colors slobbering ... I tried out with an AV cable for Nintendo 64 (which is a composite cable, our Nintendo 64 in France do not leave the RGB or S-Video), the result was the same. After many hesitations, I decided to open the cable plug ... And I understood why! In this connector is a small capacitor and a resistor, which are a pre-filtering (probably for the GameCube) for the video! So I just had to put a resistor to amplify the signal. Yes but as my RCA connector and the Game-Cube was connected together in the box, the image out of my RCA was too light! So I decided to put a switch in my case allows me to choose between either the AV Out Nintendo or the RCA!
Here is my setup.
http://www.hostingpics.net/viewer.php?id=427877SchmaII.png
And finally completed and the case according to:
http://www.hostingpics.net/viewer.php?id=40439618032012088.jpg
http://www.hostingpics.net/viewer.php?id=44741218032012089.jpg
http://www.hostingpics.net/viewer.php?id=70166018032012090.jpg
http://www.hostingpics.net/viewer.php?id=84918218032012091.jpg
http://www.hostingpics.net/viewer.php?id=90352018032012092.jpg
http://www.hostingpics.net/viewer.php?id=89502118032012093.jpg
What do you think?
(If a moderator could inscruter my images on my post, it would be great, I can not do it)
Quote from: Da Bear on February 12, 2012, 12:44:58 am
This is what I use when I AV mod Famicom
1 x 300 ohm resistor
1 x 110 ohm resistor
1 x 220uF capacitor
1x 2SA937 transistor from the Famicom (Q1)
Optionally add an extra 220 uF capacitor that you solder between PPU pin #22 and #20 to reduce some jail bars. I also remove the trace between PPU pin #21 and Q1.
I just modded my friends nes top loader and pretty much used the same parts but used a 2N3906 PNP Transistor,330 ohm and a 100ohm resistor,there were noticeable jailbars but once I isolated pin 21 on the ppu it went away,it was on par with my av famicom.
I am doing exactly what you did on your picture (chemical and ceramic capacitors, etc ...) but the bars are still there ... I even feel that it's worse ...
I capacitors 220, 820, 400, 100 uF but I do not know where to put ...
What should I do? I can not stand it any more!
Mine is HVC-CPU-07 revision...
I am French and I do not really understand what you say ...Can you add (with Paint) on this image of my PCB component locations to be added please?
http://imageshack.us/photo/my-images/856/09042012100.jpg
Post Merge: April 09, 2012, 02:29:05 am
Precisions : I've got :
- x1 1000 uF
- x1 820 uF
- x1 470 uF
- x2 220 uF
- x1 100 uF
- x2 47 uF
- x1 2,2 uF
- x1 1 uF
??? Why are you telling me then delete everything you have done the same choe on your picture? I do not understand anything! What does these blue lines on the picture?
Post Merge: April 09, 2012, 04:19:51 am
I am very sorry to understand anything but nothing seems clear to me! And I do not know much about electronics, I just do a "copy / paste" of what was on your picture when I soldered components ...
Quote from: 80sFREAK on April 09, 2012, 07:59:50 am
Ok, let's start from beginning.
The matter is lenght of the wires, when we talk about high frequency. We have high frequency on the PCB(21.477Mhz plus some combination frequencies, which give us plenty noise).
Pins of the capacitors are wires in this case. They MUST be as short as possible.
Blue lines is places where have to be soldered ceramic capacitors in your case(i sorted out with much less parts).
I have no idea, who told you to use 1uF el caps, but i would kick his ass. 220uF is minimum, but have to be with ceramic ones in parallel, because el capacitor have quite big INDUCTANCE due to design.
You can compare the lenght of capacitor pins at CPU - yours and mine.
Picture with black vinyl tape is "big mess of wires".
P.S. Your soldering joints looks not too bad for "copy/paster" ;D
P.P.S. Ah, i should check layout of ground if there any loops ??? It might be another source of "jail bars" ???
Oh I understands a little better! In fact, I must leave the ceramic capacitors in the same place, but I have to use raccourcirs and son is that right?
The 220uF capacitor, I put it where?
For in fact, I tried the different methods of this site: with capacitors between the pine and the mass of the PPU, but I have not had any satisfactory result.
> So can I take advantage once again for your kindness to tell me,
from my PCB in its current state, what should I do, step by step? ((a mini tutorial from my pcb and capacitors that I have quoted))
Thank you for your patience, 80sFREAK !
Quote from: 80sFREAK on April 09, 2012, 02:42:17 pm
No problem ;D
1) desolder EVERYTHING that i marked with red cross
2) solder ceramic capacitors as blue lines going(don't for get to cut their pins - surprize, how shorter they are)
3) upload photo.
One more trick - then bigger(in size and capacitance) ceramic(not maylar!!!) capacitors you can find, then shorter will be their pins.
Then it will be two more steps
Done ! Here's the photo I did what you told me:
http://imageshack.us/photo/my-images/685/10042012101.jpg
(
PS : If you wonder what is that black wire on the PCB, it's the shielded cable that comes out of the console and goes into my little box outside my Famicom, look at this message on this topic : http://www.famicomworld.com/forum/index.php?topic=4713.msg109867#msg109867)
For now, no difference on my TV, I look after you instructions ;)
Uh ... it's an obligation to remove them? Because I do not want to turn off the microphone and sound of my Famicom is pretty okay ...
Where are C12 ans C16 on PCB ? So if I understand, after do what you told me = no jail bars ?
For sound, I'll put it when I'll be rid of these bars ^ ^
Oh yes excuse me. You really have to parallel ceramic capacitors of 0.1 uF 220 uF of those? We can not just put solder the capacitors 220 uF on C12 and C16?
You did not answer my question: is it an obligation to parallel capacitors of 220 uF ceramic capacitors of 0.1 uF? I feel that this method does not change the screen ...
Ok, I do what you say to me (220uF 1uF ceramic +) = no difference, I still have these bars, they are not refined ...
http://imageshack.us/photo/my-images/43/12042012101.jpg . Yes, I have a voltmeter, but I do not know anything special in electronics and I do not know me use this device ....
Yes, that's what I put as my electronic components for video output ... But with this mod , you have no jail bars ? or they are fine?
Post Merge: April 12, 2012, 06:10:52 am
Sorry, 47 uF is for my audio output, for video output, i used a 220 uF, I do this schematic, i've got a beautiful image, better of my AV Famicom, look at my message : http://www.famicomworld.com/forum/index.php?topic=4713.msg109867#msg109867
I've got beetween pin 1 and pin 2 : 5,07 V
Post Merge: April 12, 2012, 06:45:53 am
I just put my line on the square "VIDEO" instead of pine PPU: I always jail bar, but the image is darker and more "runny" beurk... I will resolder my wire could before because he was there, the picture is really disgusting
Ok and if I replace this by a resistance of 330 R, what is the difference? because I did not have much material for desoldering so I wanted to know if it was really useful.
I do not know the brand of my capacitors, they are different brands.
Finally, I no longer believe that I can easily remove these bars, I think I'll wait for a clear, precise, easy, and that really works ...
Quote from: 80sFREAK on April 09, 2012, 07:59:50 am
Picture with black vinyl tape is "big mess of wires".
Of course it's a mess, it's my "trial and error" board. Trying my best with the small knowledge I have. :)
Quote from: 80sFREAK on March 24, 2012, 10:20:32 pm
What is revision of PPU? E or G?
Revision E.
I found out that 1uF ceramic capacitor between pin 22 and pin 20(GND) almost solved the problem and adding 220uF in parallel doesn't change things much. Filtering power lines doesen't change things much. Picture improved, but on the big, especially blue, areas you still can see jail bars. Or maybe i am just too fussy or my TV too sharp?
Revision G have different PCB layout and pin 22 connected to +5V. however grounding pin 22 with 1uF ceramic capacitor almost removed jailbars.
If this is result of EMI, shield over the PPU should help. Will try this little bit later.
And i think i won 8) This 8Mpix image looks awful scaled, but in 100% scale you can roughly see, what i've got. Should try another camera.
(http://i40.tinypic.com/5pmw5l.jpg)
CORRECTED
I think jail bars are result of noise from CPU on power line. You need to ground pin 40 CPU via ceramic capacitor. I used 1uF capacitor. By the way just one extra 220uF capacitor in the right place will reduce jail bars quite a lot. I tried to feed PPU via LC filter, but no visible changes.
Ha! My poor old TV and it's picture settings :-[ All good for now. I am finally satisfied.
It's a rev E PPU.
Yes, jailbars come from noise in the power line. Have you traced the noise to the CPU itself? I might give it another go with the oscilloscope when I have more time.
As a sidenote, even the NES have a lot of noise in the power line. But there are no visible jailbars in the AV out and I have noticed that the NES picture is much brighter then the Famicom.
I would like to see on an oscilloscope how the AV Famicom behaves.
Very interesting, I'll take a look and make some of my very scientific rewiring :D
What I noticed before was that the noise is only present when a game is running, so we might be a few steps closer now to isolate the source of the jailbars. :yoshi:
Size matters, ask any girl :-*
Oh I enjoy your enedeavours guys, I hope you will make some tutorials for different revision boards in the future!
80sFREAK, are you going to show us the pics of your modded famicom MoBo? it will be rather helpfull for everyone :bub:
performed the same trick as 80sFREAK has done, soldered a lot of SMD 10uF caps on the power lines, about 15 pcs.
don't feel differencies/improvement, maybe because i cut some tracks a long time ago. Will try to solder Q1 again and use his av mod schematic.
Any throughts on this?
Quote from: 80sFREAK on April 21, 2012, 04:25:36 pm
I don't think they are 10uF. Where do you take video signal from?
i don't think they are 10uF too, but when i measured everyone the capacistance meter showed right about 10uF.
have 2 meters, and they both agreed on 10uF, only few pcs have 8-9uF instead of 10, but this is really not the case. For the instance i checked a few 10uF el caps, they all have 10-11uF, so i totally relied on my measurements.
i didn't buy they just desoldered from broken PC MoBo (GA-8IPE1000-G)
video signal is taken from the lifted out from the PCB 21-st PPU pin and buffered by NPN transitor.
Quote from: 80sFREAK on April 22, 2012, 02:23:21 am
Quotevideo signal is taken from the lifted out from the PCB 21-st PPU pin and buffered by NPN transitor.
can you draw the circuit with exactly parts you have?
already done this, please consider the picture http://www.famicomworld.com/forum/index.php?action=dlattach;topic=4713.0;attach=1584;image
(rectangular boxes are resistors)
transistors: KT3107E and KT3102E (i'm sorry that datasheets on this crap is russian only) - just low-power general purpose transistors, nothing special.
Post Merge: April 22, 2012, 10:18:38 am
Quote from: 80sFREAK on April 22, 2012, 02:23:21 am
ok than, maybe just lower voltage than mine.
and for what voltage are yours?
thanks!
my transistors are okay, replacing them by another general purpose transistors changes nothing.
i lifted the pin because after lifting i see some improvements on the jailbars.
So, how the "2 transistors" works for you? is it better or worse? i guess that nothing changes.
Did some more testing this weekend.
Hooked up an AV Famicom to the oscilloscope and there was noise even in that board. Though it was mush less than the old Famicom it's still there.
Also lifted the power-pin from CPU and feed it separately from the Famicom with a bunch of caps but that didn't make any difference either.
A really good (and clumsy) power supply did make the lines fainter. But who wants a power supply bigger than the Famicom itself? ???
Haha, nice! Watching Super Mario running on the oscilloscope was fun to :D
Have not shielded the PPU. Might try that later. Finding time is my issue :(
80sFREAK, can you test your mods againt bigger than 14" TV?
Quote from: Pikkon on October 25, 2011, 07:34:30 pm
I had the same problem with the annoying buzzing and I found a fix for mine.
Just open up the player 2 controller and solder a wire just like in my pic.
(http://i4.photobucket.com/albums/y101/pikkonson/th_DSC_0227.jpg) (http://s4.photobucket.com/albums/y101/pikkonson/?action=view¤t=DSC_0227.jpg)
Once I did this the buzzing went away and the controller and the mic work fine.
Pikkon,
i joined today just to say this worked perfectly no buzzing/humming at all now - Thanks.
do jail bars depend on the total power consumption?
as far as i measured, my famicom eats about 0.5-0.6A, but NOAC famiclone with the same cartridge eats only 0.15-0.25A.
does av famicom consume less power then original red&white famicom?
Quote from: Da Bear on April 13, 2012, 07:59:46 pm
Very interesting, I'll take a look and make some of my very scientific rewiring :D
What I noticed before was that the noise is only present when a game is running, so we might be a few steps closer now to isolate the source of the jailbars. :yoshi:
Size matters, ask any girl :-*
I think I can help figure this out a bit. I compared the blue background in Super Mario Bros 1 both in a legit cart and using the PowerPak on my RGB modded AV Famicom, and the jailbars were way, way worse when using the Powerpak. Perhaps a power draw issue? The SNES Powerpak makes the thick vertical line worse as well.
Quote from: Hamburglar from MC Kids on May 02, 2012, 05:32:37 pm
I compared the blue background in Super Mario Bros 1 both in a legit cart and using the PowerPak on my RGB modded AV Famicom, and the jailbars were way, way worse when using the Powerpak. Perhaps a power draw issue?
Definitely a power issue. RetroZone's flash carts are packed full of electronic goodies so they draw quite a bit more power than a standard game cartridge and make more high frequency noise as a result.
Quote from: Hamburglar from MC Kids on May 02, 2012, 05:32:37 pm
The SNES Powerpak makes the thick vertical line worse as well.
Ever since I got a SNES PowerPak I pretty much stopped using my actual cartridges and at the same time I started noticing the dreaded vertical line more and more among my consoles, but it never occurred to me to put 2 and 2 together. Thanks! ;)
Quote from: 133MHz on May 02, 2012, 06:33:59 pm
Quote from: Hamburglar from MC Kids on May 02, 2012, 05:32:37 pm
I compared the blue background in Super Mario Bros 1 both in a legit cart and using the PowerPak on my RGB modded AV Famicom, and the jailbars were way, way worse when using the Powerpak. Perhaps a power draw issue?
Definitely a power issue. RetroZone's flash carts are packed full of electronic goodies so they draw quite a bit more power than a standard game cartridge and make more high frequency noise as a result.
Quote from: Hamburglar from MC Kids on May 02, 2012, 05:32:37 pm
The SNES Powerpak makes the thick vertical line worse as well.
Ever since I got a SNES PowerPak I pretty much stopped using my actual cartridges and at the same time I started noticing the dreaded vertical line more and more among my consoles, but it never occurred to me to put 2 and 2 together. Thanks! ;)
You are welcome! There's actually no way to get rid of the vertical bar in the SNES other than to use the SNES model 2 (aka the Jr. or mini).
The easiest place to see the SNES vertical bar is in the intro of Final Fantasy 3 US.
Edit: I should also note the SNES Everdrive does not show the thick vertical bar as heavily as the SNES Powerpak! So obviously, Powerpaks in general demand more power, and also both the NES and SNES have issues with picture quality and power draw!
Post Merge: May 04, 2012, 07:50:03 am
One other thing to look into is I see the jailbars when using my Castlevania 2 NES cart, and I do not see it when using Castlevania 2 for the FDS.
Quote from: mick on April 25, 2012, 03:05:58 pm
Quote from: Pikkon on October 25, 2011, 07:34:30 pm
I had the same problem with the annoying buzzing and I found a fix for mine.
Just open up the player 2 controller and solder a wire just like in my pic.
(http://i4.photobucket.com/albums/y101/pikkonson/th_DSC_0227.jpg) (http://s4.photobucket.com/albums/y101/pikkonson/?action=view¤t=DSC_0227.jpg)
Once I did this the buzzing went away and the controller and the mic work fine.
Pikkon,
i joined today just to say this worked perfectly no buzzing/humming at all now - Thanks.
i found this completely useless, because
1) it breaks microphone volume slider, so the level adjustment becomes impossible
2) turning off microphone is non-working, because of 1)
3) can't hear any buzzing/humming at all if mic is turned off
Quote from: 80sFREAK on May 07, 2012, 04:08:08 pm
Quote from: famifan on May 07, 2012, 11:19:21 am
Quote from: mick on April 25, 2012, 03:05:58 pm
Quote from: Pikkon on October 25, 2011, 07:34:30 pm
I had the same problem with the annoying buzzing and I found a fix for mine.
Just open up the player 2 controller and solder a wire just like in my pic.
(http://i4.photobucket.com/albums/y101/pikkonson/th_DSC_0227.jpg) (http://s4.photobucket.com/albums/y101/pikkonson/?action=view¤t=DSC_0227.jpg)
Once I did this the buzzing went away and the controller and the mic work fine.
Pikkon,
i joined today just to say this worked perfectly no buzzing/humming at all now - Thanks.
i found this completely useless, because
1) it breaks microphone volume slider, so the level adjustment becomes impossible
2) turning off microphone is non-working, because of 1)
3) can't hear any buzzing/humming at all if mic is turned off
Fot the best result you have to "rebuilt" audio circuit.It includes removing some parts on PCB and replacing some resistors. Also bypass xx368 amplifier stage, so you will get "crystal clear sound mod for Famicom"
P.S. Where is our French friend?
I'm here! Because of my studies (French law), I have no time to take care of my dear Famicom. I have not seen the previous posts, but at least, did you find a solution that really works to eliminate these bars ?
hmmm...
your proof pics ain't enough, because
0) you use 14" CRT TV...
1) i have the tv set, where jailbars become invisible for most games (maybe tv perform some filtering)
2) but on video capture device on the PC these jailbars become slightly visible and recognizable
3) if i set up color power to maximum on the tv jailbars become invisible again, because of CRT ghosting (i'm not sure about how exactly this called, i mean the situation if you see the moving of small white square on totally black screen you seen that some additional time is needed for a transition between white and black color).
so, if you want to see jailbars you need to test it against games with very bright palette such as Felix the Cat, Jungle book, Darkwing duck, and some other titles.
Quote from: 80sFREAK on May 11, 2012, 02:22:20 am
Quote from: famifan on May 11, 2012, 01:37:34 am
1) i have the tv set, where jailbars become invisible for most games (maybe tv perform some filtering)
Do you understand, why i used these screenshots?
maybe because your want to show us that "it works for me" ( equals to "it works only at my test environment"). This doesn't assume that it works in any environment
Quote from: 80sFREAK on May 11, 2012, 02:22:20 am
Quote from: famifan on May 11, 2012, 01:37:34 am
3) if i set up color power to maximum on the tv jailbars become invisible again, because of CRT ghosting (i'm not sure about how exactly this called, i mean the situation if you see the moving of small white square on totally black screen you seen that some additional time is needed for a transition between white and black color).
EPIC FAIL You should try to set brightness on maximum LOL
As for my TV set, settings about 50% except sharpness, which is 100%.
tried different color presets for my TV set and if i switching between them i can see that on some presets jailbars become visibile/invisible
I don't like color power to the maximum. But with my favourite 30% color settings, jailbars become slightly visible.
Quote from: 80sFREAK on May 11, 2012, 02:22:20 am
Quote from: famifan on May 11, 2012, 01:37:34 am
so, if you want to see jailbars you need to test it against games with very bright palette such as Felix the Cat, Jungle book, Darkwing duck, and some other titles.
none of them in my collection and i am not going to get them "just for test", except someone will contribute cart for test.
okay, in other words i just said that:
1) jailbars depend on your TV
2) jailbars depend on your TV color/brightness/etc config at all
3) jailbars depend on game
Quote from: 80sFREAK on May 10, 2012, 05:22:56 pm
There is 2 reasons, why "jail bars" exist
1)noise on power lines
hope it is resolved by adding some filtering caps
Quote from: 80sFREAK on May 10, 2012, 05:22:56 pm
2)ground layout
this thing is unbeatable unless you make new PCB design from scratch ^_^
Quote from: 80sFREAK on May 11, 2012, 07:45:15 am
Quotethis thing is unbeatable unless you make new PCB design from scratch ^_^
beatable, once you understand "why".
okay, have you ever seen PCB pics of av famicom?
it has very good ground layout, i cant imagine how i can fix old ground layout without totally new PCB design
Nintendo tried that already with the AV Famicom. It's better but not good enough.
80sFREAK, please take a look at my pics
http://ompldr.org/vZHBoeQ/sam_0071__.jpg
want to show that at the picture the jailbars become unrecognizable at all, but they are still presented!
so, the pics of TV screen ain't enough.
pic taken from video capture device (got it for less then 5$) http://ompldr.org/vZHBpOQ/smb_fami1.png - as you can see jailbars are very slight.
He is correct in that jailbars are a lot harder/impossible to see on a CRT. They only become very noticeable on a plasma/flatscreen or something without scanlines.
Quote from: 80sFREAK on May 14, 2012, 06:47:56 am
Quote from: Hamburglar from MC Kids on May 14, 2012, 06:30:48 am
He is correct in that jailbars are a lot harder/impossible to see on a CRT. They only become very noticeable on a plasma/flatscreen or something without scanlines.
Right, but he using JUNK $5 device and upscaling :o to judge the mod. facepalm.jpg
If you understand WHY jailbars appearing, you can solve it. Have you ever had a real Hi-Fi audio system, not modern junk, real one. All grounding there made as star. This is the hint.
Not doubting you but if it is ground related, why are the jailbars way stronger when using a reproduction cart or PowerPak? Wouldn't that indicate it's an issue with power draw?
please don't care about my capture device.
It produces the same picture that i can see on my CRT TV but without horizontal lines, but the pic taken from the camera can't show the jailbars at all.
so pics are provided only for showing how it is difficult to shoot jailbars on the camera. Only strong jailbars become visible on camera's pics.
80sFREAK shows us only a few pics and claims that he have resolved the issue. But i can't reproduce the results he got (maybe because i don't have 14" CRT TV with the same color setting that he had). Maybe it is just me and someone else succeded with jailbars eliminating, i don't know. Who else is succeded?
Working on it when I have time! :)
Can also inform you that on my 14" CRT I can't see any jailbars with the mod I am doing. They are still there sadly enough, as I can see them very faint on my 50" plasma.
maybe i will redesign famicom PCB when i have enough free time. Dreaming about 2 copper layers on both PCB sides (for good ground and shielding)
Quote from: famifan on May 14, 2012, 12:16:13 pm
please don't care about my capture device.
It produces the same picture that i can see on my CRT TV but without horizontal lines, but the pic taken from the camera can't show the jailbars at all.
so pics are provided only for showing how it is difficult to shoot jailbars on the camera. Only strong jailbars become visible on camera's pics.
80sFREAK shows us only a few pics and claims that he have resolved the issue. But i can't reproduce the results he got (maybe because i don't have 14" CRT TV with the same color setting that he had). Maybe it is just me and someone else succeded with jailbars eliminating, i don't know. Who else is succeded?
I have been trying to get rid of jailbars for over a year, since they are very obvious on my plasma. The only thing that did it unfortunately is the XRGB Mini Framemeister. Using Mode1 or Game1 gets rid of jailbars somehow. I don't know what magic it does, but it somehow gets rid of them.
Anyone playing 240p game consoles (NES, SNES, Genesis, etc.) on an LCD or plasma owes it to themselves to pick an XRGB Mini up, though they are quite a bit expensive.
Necro-ing the thread I know. . But out of curiosity, would it be possible to just replace the Famicom RF Modulator with one from the front load NES to get the desired AV out?
Good thinking, but no. The main board of the NES is also responsible for the less "jail-barred" video signal. So yes, you can get AV out this way, but you will still get the jailbars (vertical lighter lines through screen).
Well with that being said, couldn't you harvest the parts from the NES board needed to clear the jail bars? That and wouldn't the NES give you basically a drawn out map of how to assemble it? Just rambling so if it's been mentioned don't mind me.
Yes it has been mentioned, it's the way the traces are drawn on the PCB and the placement of the parts, not the parts themselves that matters here.
So more like weak traces and weak grounds on the famicom board?
Quote from: HokusaiXL on June 05, 2012, 05:40:53 pm
Necro-ing the thread I know. . But out of curiosity, would it be possible to just replace the Famicom RF Modulator with one from the front load NES to get the desired AV out?
I don't think there's enough room inside the Fami for the NES RF/AV box, plus you'd have to drill holes for the jacks and channel select switch. You're really much better off just doing an AV mod.
Quote from: 80sFREAK on June 14, 2012, 06:37:18 pm
Tried to take photos, but pics looks far away from what i see in real. Are jailbars really bug or just feature to get extra color(google zx spectrum multicolor demo)? For the first looks jailbars repeating at each 8th pixel, which makes sence - it's a bug on power line(and SMD capacitors and proper wiring changing picture quite a lot) or either shift register(it's inside PPU, so have to accept this as is). BUT, how to explain different pattern of "jailbars"? Keep in mind, that LCD TV's upscaling picture and algorithms can be different between different brands/models
http://www.famicomworld.com/forum/index.php?topic=4713.msg102415#msg102415
CHR A13
for quick test: just touch to CHR A13 PPU pin and to Video out pin by 2 your fingers simultaneously and look at what is going on the screen.
:pacman:
Post Merge: June 16, 2012, 09:02:44 am
i'm thinking about subtractioning CHR A13 signal from video signal by opamp. But it might fail.
Post Merge: June 16, 2012, 12:23:44 pm
Quote from: 80sFREAK on June 14, 2012, 06:37:18 pm
2)Lode Runner real IC's 4.90V on ROM chip - blue background absolutely clean with no jailbars
3)Mario Bros glop-top 4.95V on ROM chip - faint, but visible jailbars, white clouds are absolutely clear
4)Yoshi no tamago glob-top MMC1 4.95V on capacitor - jailbars on white screen, NO jailbars on blue screen. Also
LOL, what did you measure? 4.95 or 4.90? what equipment did you use?
4.95 - is okay for 7805 output, %2 tolerance. How did you get 4.90?
Quote from: 80sFREAK on June 16, 2012, 05:31:01 pm
Quote from: famifan on June 16, 2012, 08:59:00 am
for quick test: just touch to CHR A13 PPU pin and to Video out pin by 2 your fingers simultaneously and look at what is going on the screen.
:pacman:
Post Merge: June 16, 2012, 09:02:44 am
i'm thinking about subtractioning CHR A13 signal from video signal by opamp. But it might fail.
Post Merge: June 16, 2012, 12:23:44 pm
Quote from: 80sFREAK on June 14, 2012, 06:37:18 pm
2)Lode Runner real IC's 4.90V on ROM chip - blue background absolutely clean with no jailbars
3)Mario Bros glop-top 4.95V on ROM chip - faint, but visible jailbars, white clouds are absolutely clear
4)Yoshi no tamago glob-top MMC1 4.95V on capacitor - jailbars on white screen, NO jailbars on blue screen. Also
LOL, what did you measure? 4.95 or 4.90? what equipment did you use?
4.95 - is okay for 7805 output, %2 tolerance. How did you get 4.90?
You know, boy, cooper on layout have resistance and Ohm was very clever guy. Should i continue?
As about CHR A13 - it gives 4 pixels wide stripes, not 1 pixel wide "jailbars".
Played around GPM-02 little bit. Rewiring CHR A13 gave amazing result... jailbars now on every odd pixel, but it can be result of upscaling
dear 80sFREAK, i don't want to hurt you, but to rely on your measurements you need the device with very high accurancy. If you used digital voltmeter/multimeter you've fucked up twice. Should i continue?
Not sure if you trying to troll me or just stupid. The simplest way to figure out that is just to suggest you to calculate how much is the copper layer resistance should be for reducing 5V to 4.9V. Could you calculate this? ;D
already retraced CHR A13, and going to retrace tracks from #24, #23 ppu pins.
Quote from: 80sFREAK on June 17, 2012, 02:51:30 am
Quote from: famifan on June 17, 2012, 01:51:59 am
[
dear 80sFREAK, i don't want to hurt you, but to rely on your measurements you need the device with very high accurancy. If you used digital voltmeter/multimeter you've fucked up twice. Should i continue?
facepalm.jpg
Try to measure voltage in the different parts of your Famicom and with different cartriges. Result will surprize you :)
I wonder, if i get can get somewhere LCD screen without upscaling ???
well, i will try if i have the such high accurancy device. What is blocking you from answering some my question about your equipment? and how did you measure it.
e.g. if you use true 1% tolerance equipment and choose 0-10V gauge, your measurement accurancy step will be 10V*1% = 0.1V. In that case your device can't guerantee distinction between 4.90 and 4.95 even you've got it on the screen. Should i continue feeding you? ;D
what is your device tolerance/accurancy?
Quote from: 80sFREAK on June 17, 2012, 04:48:09 am
Quote from: famifan on June 17, 2012, 03:48:39 am
well, i will try if i have the such high accurancy device. What is blocking you from answering some my question about your equipment? and how did you measure it.
e.g. if you use true 1% tolerance equipment and choose 0-10V gauge, your measurement accurancy step will be 10V*1% = 0.1V. In that case your device can't guerantee distinction between 4.90 and 4.95 even you've got it on the screen. Should i continue feeding you? ;D
what is your device tolerance/accurancy?
facepalm.jpg
"1% tolerance" is about little bit different thing, but nice try :) I will try to explain in simple words.
Let's say you have 10bit ADC and measuring 0-10V range
What is minimum step of measuring? 1/1024th of the range, which consist of 1024 steps.
Is it accurate? Yes. What is the value of voltage if we read 55 from ADC? It's exactly 55/1024th of maximum range. But... what about precision voltage source for ADC? It's analogue, not discrete. And it might have "1% tolerance", so readout will be little bit off. But if this source not drifting during measurement, nothing wrong - you will get relative value of voltage and still can see 1/1024th steps on your measurement.
LOL, LOL, LOL again. Serious equipment has some certificates that proves it's accurancy (let's say for 1 year or 2). And it directly says, that this device has xx.xx% tolerance for DC measurements, yy.yy% tolerance for AC and so on.
and if you got two results from ADC
first is 55/1024th
and the last is 999/1024th. The last is better because it contains less ADC quantization errors.
Quote from: 80sFREAK on June 17, 2012, 04:48:09 am
So, my answer is "my device is accurate enough to measure changes more than 0.01V(0-10V range) on relative scale". Relative - this is keyword.
so, in that case you device need 0.05% basic occurancy or even better.
it seems that you have the certificated seriuos device that costs more then 1k$ ... Really :o?
http://en.wikipedia.org/wiki/Multimeter#Digital
QuoteFor example, a meter reading 5½ stable digits may indicate that one nominally 100,000 ohm resistor is about 7 ohms greater than another, although the error of each measurement is 0.2% of reading plus 0.05% of full-scale value.
troll harder
don't care about me.
So, did you agree that you can't interpret your measurements correctly?
I've done some testing with my famicoms. If i use the same famicom and tries Super Mario from a normal cart i get big jailbars, but if i play the same game from my FDS i get really weak jailbars ???
Feels like there's something with the carts itself? :upsetroll:
Quote from: 80sFREAK on June 20, 2012, 06:53:55 am
Quote from: famifan on June 19, 2012, 11:22:03 am
So, did you agree that you can't interpret your measurements correctly?
Nope.
Ok, back on track. GPM-02 and 07 have similar layout for CHR Axx line, so this is not the case, but grounding. I will make one experiment, PowerPak related and update results.
do you have an oscilloscope?
i don't know what you've measured, but with my shitty analog oscilloscope i've seen that VCC is polluted by noise with the PPU/CPU clock frequencies. Yeah, the AC shunt capacitor around every IC reduces that noise, but it is still present anyway. And the Peak-to-Peak noise amplitude is high enough to cause the differences like 4.9 and 4.95.
also, with my unserious uncertificated equipment i can't see any notable VCC differences. Also i've checked the copper layer resistance and it is too small to make this huge VCC reducing.
i beleive you are smart enough and can give me your copper layer resistance approximation that can cause 0.5-0.10 voltage drop. ORLY?
At the risk of interrupting the last couple of pages of fun, I just AV modded the Famicom I got from 80sFreak, and thought I would throw in my two cents.
I used the directions in the second post of this thread, using the Q1 transistor removed from the board, and used Da Bear's recommendation of using a cap between pins 20 and 22. The result was pretty good, but I had faint jailbars that were particularly noticeable with black screens, like the beginning of Gradius. I took it apart again, lifted pin 21, and put in some ghetto RF shielding around the video amp (probably didn't do anything, but it can't hurt) and the jailbars are completely gone.
One thing worth noting, the video is pretty clear, but it doesn't look quite as bright and colorful as my AV modded NES 2. I'm going to check my notes to see what resistor/cap values I used on it, as I'm not sure if it has something to do with the video amplification or if it's simply a hardware difference. I may duplicate the NES2's amp and check to see if there is any difference.
*shrug* I just followed the directions, and they worked. Unsure if the cap did anything, I didn't try it without one.
Quote from: 80sFREAK on June 20, 2012, 03:39:08 pm
Quote from: famifan on June 20, 2012, 10:55:51 am
i beleive you are smart enough and can give me your copper layer resistance approximation that can cause 0.5-0.10 voltage drop. ORLY?
Yeah, no problem, just tell me how big is current. Ohm manipulated with three parameters :)
By the way, you should check noise on the ground lines.
afair, total famicom current consumption measured by myself some months ago is laying around 0.5A +-100mA (the fluctuation depends of the ROM ICes that's used in cart. Old TTL roms eat a lot of current). I'll made more accurate measurement later if you need.
Post Merge: June 22, 2012, 06:20:01 am
Quote from: 80sFREAK on June 20, 2012, 08:28:40 pm
Ummm pin 22 is /SYNC, but running in parallel with pin 21. And they are pretty close inside PPU case.
PPU's pin 22 is connected to VCC ( /SYNC: When low, forces internal state to reset/blank).
Hello all, on a recent trip to Japan, I found a shop selling used Famicoms that were tested and cleaned, so I bought one to bring home. Having had a Famicom since the early 90's, I found my old FDS and plugged it in. Needless to say, it started up fine, but the video signal was horrible on a modern plasma. I went searching and found the AV mod, which I performed (used a 1/2W 300 ohm resistor, a 1/4W 100 ohm resistor, a 2N3906, and a couple 16V 220uF coaxial caps). When I plugged it in, I would get a clear video signal, only it lasted a few milliseconds, and flashed periodically (showing the updated picture) every 1s or so.
At first I thought it might have been the parts I used, especially the PNP, so I tried bypassing the circuitry and hooked the TV up directly to the video pin, and though much attenuated compared to using the transistor, the video signal did the exact same thing. Not having removed Q1, I plugged the RF back in, and the picture was as it always has been, no flashing frame skipping. I plugged it into my receiver, thinking maybe it's the TV, but the receiver won't even acknowledge the signal and showed nothing. Not only this, but no sound was being generated (I couldn't tell if RF generated sound because my plasma doesn't have speakers). I assume if it's generating a good signal for 20ms every 1000ms, it's probably not enough for the receiver to recognize it (unless my odd Dell TV really doesn't like it somehow). I double checked the voltage at the 7805, which is steady (not periodic) at 4.92V, and tried moving the coax RCA cable ground to the same ground as the 7805 is using (in case the ground plane was being affected by something periodic), but no change. My next step is to take it as is and try it on another TV, but I'm hoping that's not it.
Ideas? ???
All hail to GohanX :coin:
Jailbars are gone after PPU has been shielded with a piece of copper foil!
Quote from: 80sFREAK on June 30, 2012, 07:52:03 pm
2 famifan well done, just no need shielding behind the crystal in the chip. By the way, did you shielded bottom of PPU as well?
PPU had been wrapped by coil, so the bottom was shielded too. As you can see i've put the hit-resistant insulating insertion between the coil and the PCB
Famifan: Well, that's not exactly what I did, but it works! I built my amp on a tiny piece of breadboard, wrapped it in foil and tucked it in the side of the case where the controller cords run up the side of the system.
What do you have going on there where the RF board normally goes? Did you yank it and build a standalone power board? I had been thinking of doing that so that I would have room to mount proper AV jacks to the back of the system.
Quote from: GohanX on June 30, 2012, 08:28:57 pm
Famifan: Well, that's not exactly what I did, but it works! I built my amp on a tiny piece of breadboard, wrapped it in foil and tucked it in the side of the case where the controller cords run up the side of the system.
What do you have going on there where the RF board normally goes? Did you yank it and build a standalone power board? I had been thinking of doing that so that I would have room to mount proper AV jacks to the back of the system.
yeah, needless RF circuit had been completely removed.
i've just made some improvements such as:
1) adding good heatsink for 7805 (afair yanked it from old 66/100MHz cpu). It is also the bigget heatsink i've found that fits into tiny famicom case.
2) adding some electrolytic capacitors for 7805
3) connecting the turn on switch to the 7805 input
av jacks.... i have 1.5m long hardwired cable with jacks that goes out of famicom.
I may duplicate that sometime. I've actually got some 7805 heat sinks laying around I pulled from dead Genesis model 2's.
Quote from: 80sFREAK on June 30, 2012, 04:51:45 pm
Any chance to try with another TV?
Yep, my guess was right...tried another TV and it worked. Not sure why the comp output won't work on my both my TV and my amp, but it looks like I'll have to live with RF for a while longer, until I get another TV. Sound seems fine as well, and was able to push that through the amp.
li Arc
I tinkered with my Famicom again today, and removed the power board. I relocated the video amp to the back of the Fami and installed a proper video jack in the hole where the RF jack used to be. I was running short on time so I didn't cut out any holes for the audio, and I just ran the RCA cable out one of the TV switch holes. I also put on some foil to cover the PPU instead of the video amp, although I didn't quite go as hardcore as 80's freak and put it on the underside.
The result: Perfect video out of the Fami. No jailbars, and none of the slight interference I was getting from using a crappy video cable. The video is on par with my Toaster and modded NES 2 (both use the same video amp) but the brightness is a shade darker, which actually makes the colors pop a bit more. For composite video, I'm quite impressed.
Maybe next weekend I'll properly install the audio jacks, I was thinking of filing away the channel switch holes and putting them there, although the three holes (dual mono audio) would have weird spacing. Still, I think that's the neatest way of doing it.
Also, when I removed the power jack, I chipped the plastic a bit. It doesn't interfere with operation, but it's an eyesore. I don't suppose anyone would have a spare power jack from a parts system they'd be willing to sell? I know I can get them at Radio Shack, but I fear they probably wouldn't fill the hole in the case properly.
QuoteI can give you some for free, just pay shipping :)
Awesome, I'll shoot you a PM!
since the jailbars disappeared i think it's time to write a short and complete mini "how to"/FAQ separate thread about AV modding. Who wants? Maybe later it will become an artictle for famicomworld.com.
Agreed. People shouldnt have to read through this whole thread to get the most of their famicom's composite video signal.
If somebody produces a good write up, we'll sticky the thread. (A future site article is also a possibility).
Quote from: famifan on July 05, 2012, 10:46:00 am
since the jailbars disappeared i think it's time to write a short and complete mini "how to"/FAQ separate thread about AV modding. Who wants? Maybe later it will become an artictle for famicomworld.com.
...at least for two models CPU-07 and GPM-02, the rest is similar. :)
Quote from: jpx72 on July 09, 2012, 04:04:50 am
...at least for two models CPU-07 and GPM-02, the rest is similar. :)
I think that's the main reason we don't have an A/V mod article on the main site -- it would be preferable to have a guide that covers all models.
for workaround in general you can rebuild discrete buffer + amp outside instead of using the buffer from fami's PCB.
I'm not going to sticky a thread so that people can read through 19 pages of conflicting data ;D
I went through the thread last night and I'm not sure what the solution is, exactly. Is it some combination of the instructions on jpx72's page plus some copper tape on the PPU? I'm a total newbie when it comes to console modding, so that's really the most I could get out of the thread. There are some other ideas/solutions in the thread, it seems, but I can't make sense of them.
Quote from: UglyJoe on July 12, 2012, 06:31:20 am
Is it some combination of the instructions on jpx72's page plus some copper tape on the PPU?
to summarise the steps:
1) shield the PPU crystal by some copper foil
2) use any AV-amplifier circuit you want. At least 3 variants you can find in this thread.
3) if unsatisfied with results (e.g. to much jailbars) - add ceramic capacitors as closer as possible to every ICs' power pins. 0.1uF al least. It is better to use SMD caps with the biggest capacitance you can find (also, can be a little expensive)
it looks like the other steps are unnecessary.
I would add lifting/cutting the composite video pin, that made the biggest difference in eliminating jailbars on my system.
Hi there, first time poster, longtime anon-lurker.
I've tried my unworthy hands at doing the AV-mod following the schematics by Kyushu but now I've hit a wall and I was hoping that you guys could help me out (hopefully without tearing me a new one).
The problem is that my TV just displays a blue screen when I hook up my Famicom (HVC-CPU-07 if that helps any ^^), I've checked all the cables and joints and I've even re-soldered the whole thing 4 times with new components just to end up with the same problem.
I'm guessing that I've managed to put something backwards or something but hey, trial and error is a great teacher!
Maybe you need to clean the cart.
The carts are clean and I've tested them in another unit so I know that that's not the issue. Tried once again this morning and this time I got more colors! (One at a time but hey, it made me happy for some reason), I have now seen blue, purple and grey!
I'll try to get some pictures but at the moment my camera is having a seizure or something.
Perhaps it's the transistor, I only had some PNP 9015C 100mA 20V ones at home, could that be the bastard in the mix? :(
if you see color and not only blank/black/blue screen, your transistor is 99.95% okay
i suppose this is the bad connection issue. Try to find the "right" cartridge position within the slot.
I get one color at random each time I reset the console, it's either blue, grey or purpleish, no movement or changing of colors except for when I reset.
I'll give jiggeling the cart a try, thanks for the suggestion :)
Quote from: 80sFREAK on July 14, 2012, 03:11:17 pm
Nothing to do with AV mod. Clean slot first.
Yeah try the credit card+ old t-shirt cleaning trick :D Just be gentle, you don't want to bend any pins.
Do you ground the copper tape somehow?
Interesting! I've never used copper tape before. So, you just solder directly on it?
Cool! I will definitely attempt this. Thanks for clarifying, 80sFREAK!
Thanks for the tip! I'll use rubber gloves when doing it, then.
Quote from: 80sFREAK on July 20, 2012, 09:05:32 pm
methanol
omg, do you have access to this toxic shit? :o
Hi there,
I'm new to the famicom scene.
I'm Dutch so I have a pal TV.
And i have a GPM02 famicom with a megadrive 1\ genesis 1 power supply.
But I have a problem. I desoldered the 2SA937. Something went wrong and Pin C broke.
I tried to bridge it with enough of solder, but that didn't work.
When i tried to turn it on it doesn't give a signal to my tv.
I don't even know if this famicom is working.
Can I check this with a 2200ohm resistand and a LED?
Anyhow, is there somekind of replacement transistor instead of the 2SA937?
Thank you in advance.
Regards
koffieleut
Of course you can use any PNP transisor, don't worry.
Fixed. fuse was blown. now my modded famicom works.
Hey there guys! Got my Famicom in the mail today and on the board it says HVC-CPU-08. The tutorial for removing and placing the transistor is only for rev 01-07.
Should I go ahead and do the same anyway?
Ps. I'm new to console modding, any help would be most helpful :D
Can you please do a couple of hi-res photos of your board? It's quite rare to find this revision...thanks!
Sorry, these are the best photos I can take right now.
(http://i2.photobucket.com/albums/y48/Gainax_Aesir/IMG_0284.jpg)
(http://i2.photobucket.com/albums/y48/Gainax_Aesir/IMG_0283.jpg)
(http://i2.photobucket.com/albums/y48/Gainax_Aesir/IMG_0281.jpg)
(http://i2.photobucket.com/albums/y48/Gainax_Aesir/IMG_0286.jpg)
(http://i2.photobucket.com/albums/y48/Gainax_Aesir/Back.jpg)
(http://i2.photobucket.com/albums/y48/Gainax_Aesir/IMG_0287.jpg)
That board still has a 2SA937 so you could use that in an AV mod no problem.
Just follow the instructions on the tutorial for revs 1-7?
http://jpx72.detailne.sk/modd_files/fc/avmod.htm
Quote from: GAINAX on October 18, 2012, 03:17:20 pm
Just follow the instructions on the tutorial for revs 1-7?
http://jpx72.detailne.sk/modd_files/fc/avmod.htm
That's right.
Thanks for the help! I'll get to work on that now :D
Gys what is that shiny sticker thing on the PPU? I have seen multiple boards with this but I don't own one. Is that an early effort on shielding the PPU? If so, why only some models have it?
To GAINAX: Thank you very much for the photos! Those are awesome!
Also, I have never seen a board with SOIC RAM! I have to check out my board photo repository for the 06 model, maybe I just haven't noticed that.... Okay I checked my pictures folder and found the SOIC RAMs on 06. Funny I haven't noticed them before :)
I believe that's an aluminum self-adhesive sheet that is used for rf shielding...
Quote from: 80sFREAK on October 19, 2012, 02:07:18 am
heatsink.
I thought of adding it to my assumption but it seems unlikely to be true... interesting... is it because this particular revision has a different ppu ?
Well the mod worked in the end :D Thank you guys again for the help and tutorials! :D
Now time to play me some Rockman :D
Hey there! Having played with my Famicom for a week now I noticed early on some strange diagonal lines on the screen as well as having jail bars.
(http://s11.postimage.org/4b3u6kosj/diag.jpg)
If you look VERY closely, you can see some lines going from the top left corner of the image to the bottom right. Whenever I play ANY game they seem to flicker all over the show. Sometimes they'll stay confined to the bottom half of the screen, and then all of a sudden they will fill up the entire screen.
eg. When I play Rockman 1 on Cutman's stage they stay on the bottom half of the screen. but when I press the start button to call up the item select screen, the diagonal lines suddenly engulf the entire screen. I guess it might have to do with however many sprites are on screen at once? *Shurgs*
I think I can live with the jail bars, although they aren't as feint as I thought they'd be having followed the instructions here (http://"http://jpx72.detailne.sk/modd_files/fc/avmod.htm"). I guess it's got to do with my revision of the board: hvc-cpu-08.
Any help would be much appreciated :D
Edit: Thought I should mention I'm not using any shielded cable right now.
Quote from: GAINAX on October 26, 2012, 04:47:35 pm
Edit: Thought I should mention I'm not using any shielded cable right now.
Those diagonal lines you're getting might be interference, try using shielded cable and see if it makes a difference
Not on purpose, just all I had at the time.
Just as a note, I finished trying out 80sFREAK's AV mod on a top loader I've been working on and it has some issues. First off, the contrast is a bit off and it seems to go out of sync every time there's a bright white flash on the screen. I normally use kyuusaku's schematic for these mods so it looks like I'll be going back to that.
So on the video circuit its okay to use a 22uf instead of 33uf? 33uf seems difficult for me to find locally, but if there is improved picture performance then I will order one
Thanks
Quote from: 80sFREAK on October 30, 2012, 04:49:54 pm
I tried 22, 33 and 47uF, with my TV can not see difference
did it depend on TV's input capacitance ?
never used the capacitors on AV outputs because i can't feel the differences
Looks like it depends on region - capacitors in the TV or not
http://jpx72.detailne.sk/modd_files/fc/avmod.htm (http://jpx72.detailne.sk/modd_files/fc/avmod.htm)
Sorry if this is maybe a bit off topic but In this tutorial it is recommended to use a 220 uf capacitor on the Audio output ( connector pin 46)
However in other tutorials, I think when connecting directly on the cpu pins such as the US NES stereo mod, a 1 uf cap is used in the opposite polarity.
I was wondering why this difference.?
I have not yet made the Video mod on my famicom but i want to do the audio connection now to record some music with the hardware.
Thanks.
Quote from: MaxWar on November 04, 2012, 08:22:27 pm
Sorry if this is maybe a bit off topic but In this tutorial it is recommended to use a 220 uf capacitor on the Audio output ( connector pin 46)
However in other tutorials, I think when connecting directly on the cpu pins such as the US NES stereo mod, a 1 uf cap is used in the opposite polarity.
I've gotten away without using any capacitor, although I usually tap the audio from pin 3 of the ribbon cable (the point directly above pin 56 of the cart connector) on older revision Famicoms. For newer ones like the HVC-CPU-GPM-02, I found that tapping the audio directly from the cart port gives you muffled sound, so I had the audio come from a resistor connected to pin 46. Sounds much nicer that way.
Quote from: 2A03 on November 04, 2012, 09:39:06 pm
I've gotten away without using any capacitor, although I usually tap the audio from pin 3 of the ribbon cable (the point directly above pin 56 of the cart connector) on older revision Famicoms. For newer ones like the HVC-CPU-GPM-02, I found that tapping the audio directly from the cart port gives you muffled sound, so I had the audio come from a resistor connected to pin 46. Sounds much nicer that way.
I have the HVC-CPU-07 and those two points are directly connected so it would not matter on my version. I guess you could skip the cap altogether but i thought the point of it was to add some sort of buffer to protect the inner circuitry?
I don't understand the technical stuff behind it but without the capacitor on sound output I wasn't able to get the sound from Famicom when connecting directly to a "line-in" of a sound card of my computer. There was a strong buzzing sound instead. Something about galvanic separation or something... ???
maybe it's because the output volume is too high? on my lcd set I have to put the volume to 1to8/100 , anything higher is just too much!
Quote from: 80sFREAK on November 05, 2012, 01:24:55 am
QuoteI found that tapping the audio directly from the cart port gives you muffled sound, so I had the audio come from a resistor connected to pin 46
???
Yep, there's some kind of resistor (or at least what looks like a resistor) labeled "FC1" directly connected to pin 46 and tapping the audio there provides a nice and clean signal. This is just on the HVC-CPU-GPM-02, I don't think it's present on any older revisions.
Ok, about the Capacitor on audio output ( Connector pin 46) question, i did some experiments.
I made 4 recordings of Castlevania III intro.
A. without any cap
B. 220 uf cap with + on pin46
C. 1 uf cap with + on pin46
D. 1 uf cap with - on pin46
All recordings are made with the same parameters.
There is quite an audible difference you will see. ;D
I will tell you right now that background noise seems to vary seemingly at random ( my experimental setup is a bit dodgy and i do get some interferences) but the level do not seem to depend on what capacitor was used. If you go at the end of each recording i left some ( silence) with only the background noise. This noise is caused by the famicom as it disappears if i remove power. I expect it would be much less if i used shielded cables and the mod was made with shorter wires.
Here are the files.
http://www.2shared.com/file/XQLkgomH/FamicomCas3-Capacitor-soundtes.html (http://www.2shared.com/file/XQLkgomH/FamicomCas3-Capacitor-soundtes.html)
Quote from: keropi on November 05, 2012, 05:18:22 am
maybe it's because the output volume is too high? on my lcd set I have to put the volume to 1to8/100 , anything higher is just too much!
No this is not the problem, try it yourself - connect the audio without cap directly to PC audio card.
Quote from: 80sFREAK on November 06, 2012, 11:45:37 pm
With 1uF you will have little bit less bass, it's obvious. Usually "sound" capacitor is 10-22uF. "Background noise" also can come from 2nd pad cable and mic. If you want pure 2A03 sound, you have to rebuild most of audio circuitry. Or at least remove sound line from mic. As about sound files - with no cap, normalized(?), so can not be compared with others. Wrong polarity will destroy capacitor, but not immediately. Ummm, what else you can do - add big ceramic capacitor to each microchip and 100-220uF capacitor in parallel. Do proper shielding, include shielding CPU(like PPU, but from pin1-40)
P.S. audiophilia and 8 bit sound ???
Yes I am an audiophile and I like 8 bit and 16 bit tunes alot. :)
As for the Normalized file, i did this for proper comparison. Usually I always Normalize all my audio recordings but when i recorded with capacitor in the line, i had gotten proper volume on first try. ( Full amplitude without clipping ) So i exceptionally did not normalize them. Without Capacitor, the sound was lower and very heavily cut in the bass. In fact it sounded like it was out of a telephone... This is why i normalize it, to bring the volume back toward the level of the other recordings. This is in fact to allow them to be more properly compared.
The sound without a capacitor on is very bad. I cannot say exactly why as i do not properly understand the theory behind it.
If you listened to my recording, i think you should notice that it sounds ''fuller'' with the 1 uf cap VS the 220 uf. The difference is not extreme but still audible. The 220 uf cap seems to have cut some of the low-mid frequencies.
Maybe i will do another test with a 10 uf cap as this is what is used in the Famicom RGB + Sound separation kit i bought.
Thank you for the recommendations 80sFREAK. When i get back to my Famicom for permanently modding it, i will possibly experiment with what you said.
P.S I also made a new series of recordings. This time I compared 4 different games on different machines.
Famicom, Sharp Twin, Famicom AV and US NES . Stay tuned, will make a thread about this later today :D
Help please!
I followed 80:s Freaks tutorial but I don't get any signal at all. I've both tried the Q1- transistor and a 2N3906 pnp transistor. I know that the famicom did work before I started. Does anyone have a clue of what the problem(s) can be? It's a 1984 model by the way
This one is with a 2N3906 transistor
Post Merge: November 13, 2012, 11:28:57 am
Hope you can make a diagnosis with this picture, were not able to attach more files. Forgot to mension, I used a 47 uF capacitor instead of a 33 uF
It's hard to tell but it looks like you're not getting 5V because of how you wired up the resistors. The 150 ohm resistor and the positive lead of the 47 uF cap are supposed to be tied together to the emitter, with the other end of the resistor going to a 5V source and the negative lead of the cap going to the 110 ohm resistor.
Just checked with a multimeter, the wiring are conductiv and I get voltage. How do I check the transistor?
Quote from: Julhan on November 14, 2012, 07:53:29 am
How do I check the transistor?
you'll do it with ease ;)
at first check both p-n junctions, just think of them as 2 diodes connected to B (E->B and C->B). Just to be sure that DC current can run into that direction, not another.
then check current gain if you multimeter can do that
take as a rule to check every component right before the assemling
The transistor seems to be fine as well..
the voltage is 4.95
exactly, I played smb 3 with the RF switch before starting the mod. Can the PAL-tv be a problem?
try playing with an lcd tv set thas is compatible with both pal and ntsc (99% are)
Dang, I tried the AV mod on my CPU-07 famicom and I still get nasty jailbars.
I followed the steps on the page http://jpx72.detailne.sk/modd_files/fc/avmod.htm (http://jpx72.detailne.sk/modd_files/fc/avmod.htm)
I even did the extra step of unsoldering the PPU, putting it in Socket and covering the underside with grounded metallic tape ( I could not find the copper one so i used aluminum tape)
I followed the steps exactly. I made the circuit very compact, I used Tantalum caps because i could not find Ceramic caps of the proper value. I respected the polarity and used shielded video cable.
Am i the only one?
Quote from: MaxWar on December 01, 2012, 10:04:49 pm
Dang, I tried the AV mod on my CPU-07 famicom and I still get nasty jailbars.
I followed the steps on the page http://jpx72.detailne.sk/modd_files/fc/avmod.htm (http://jpx72.detailne.sk/modd_files/fc/avmod.htm)
I even did the extra step of unsoldering the PPU, putting it in Socket and covering the underside with grounded metallic tape ( I could not find the copper one so i used aluminum tape)
I followed the steps exactly. I made the circuit very compact, I used Tantalum caps because i could not find Ceramic caps of the proper value. I respected the polarity and used shielded video cable.
Am i the only one?
You should really go with copper its a much much better ground you can get a thin copper sheet if you can't the adhesive copper tape
have you tried replacing the transistor and the resistors its super cheap and can't hurt to try
also this may sound stupid but have you tried to adjust the brightness on your tv I notice a lot of people have their tv adjusted too high on brightness scale which may be appropriate for modern gaming not some much for old school stuff
Thanks for reply.
Well, I looked at a few convenience stores and they did not have the copper tape. I guess i could look at one of the big surface place.
I used the Transistor from the board. Did not try to replace it. Tut said it was the best choice.
As for replacing the resistors, honestly i dont see how it could change anything.They are just standard 1/4/w resistors, they work or not, right?
Seems to me that this problem is interference related. Maybe i put some part too close to some trace or something?
Also, for the 0.1 uf cap, they did not have ceramic caps at my electronic store so they sold me a Tantalum one. Unlike the 33 uf one, it does not appear to have any polarity.
Could this cap be a problem??
My brightness is not too high. Its about in the middle. It does not look that much bright actually so i dont think thats the issue.
The jailbars are visible enough to be distracting.
Quote from: 80sFREAK on December 01, 2012, 11:24:30 pm
Did you grounded shield? Did you built your video amplifier around pin20? Did you disconnected pin21 from PCB? Did you added some capacitors on the power rails? If one of your answers "no" - you didn't followed "how to". Read it again and do it again. Once you follow exactly the steps, you will get a good result.
I grounded both cable shield and Metallic tape on PPU.
Well, i followed exactly the steps in the link i gave ( The orange page ) and it does not tell me to do all those things. ( except for vague allusions in step 8 )
But i see now that on the same page there is a link to a thread by you that provides different instructions along with more details.
The instructions on the orange page says it is the best method so this is what i followed.
But it does not even make you disconnect pin 21 from board, It makes you use the existing trace to connect pin 21 to the base of transistor.
Ill do more tests tomorrow, going to sleep now.
Post Merge: December 02, 2012, 05:40:42 pm
Alright, I redid the mod a bit differently, and i swear, im not having any luck, it does not seem any better. ( OR very very slightly )
Jailbars are there and not very subtle.
I did not lift the pin 21 but i cut the Trace on the underside of the PCB, it no longer connects to anything but the mod.
Im not 100% sure what you mean by building the amp around Pin 20 ( Ground ) So i used pin 20 for all my ground connections.
I have two 0.1 uf ceramic caps ( i found some ) connecting 5v to ground Between pin 22 and 20 of PPU and between Vcc of cpu and ground.
Here are some pics.
Open in separate window to zoom.
What should i try at this point? Make the circuit on the top of PCB and completely lift leg 21?
(http://i.imgur.com/OL3j2.jpg)
(http://i.imgur.com/PDaRr.jpg)
I added another one between pin 40 of ppu and ground. How many of them do i need to add?
I have 3 so far and it does not seem to improve very much.
Post Merge: December 04, 2012, 04:00:26 pm
Well, I tried a different circuit, the one on consol5
(http://console5.com/techwiki/images/4/4d/NES_Toploader_AV_Schematic.png)
And it works better for me. Almost completely eliminated jailbars.
They do not show at all in most games but you can still faintly make them out on pale colored uniform backgrounds like in the intro of crysis force, Or the splash screen of the goonies.
Adding caps on the power lines seemed to help a bit but switching to this circuit made the biggest difference on my machine. I don't know why.
Maybe ill try adding further more caps and see if i can get to completely 100% remove the bars even on pale uniform backgrounds.
Hello! I am very new to the forum so bear with me. I got a famicom from ebay. I have tried using the NES RF cable, TV channel 95/96, VCR, etc etc but cannot get the famicom to work. It has been modded previously as the ch1/2 switch was removed. I suspect the famicom has been modded to PAL RF, so my only solution is the AV mod. Too bad I threw away the multi-system TV many years ago.
The sound works. I use pin 46 from the cart connector. I got no luck on video out. Actually now I am not even sure if PPU pin 21 works. I had built the video circuit using a prototype board, but now I want to isolate it and test PPU pin 21 instead. How should I connect this pin to the TV? All I got now are many RCA video connectors. Should I use one and hardwire it to pin 21? By doing this I must desolder the transistor Q1 from the board correct? Many thanks! I want to make sure pin 21 gives out video before troubleshooting on the video circuit that I built.
People searching for the best AV mod, please don't post another schemes for god's sake, read this topic:
http://www.famicomworld.com/forum/index.php?topic=8080.0
you cannot find a better solution, it's simply not possible!
Clearer instructions would be nice though. :)
For the basic mod you can use my webpage with step by step inatructions based on 80sFREAK's findings. If you want to make yourself a crystal clear image, you need a lot more experience and you won't be asking for "clearer" instructions.
Hello again! Sorry for no photo last time as I was not ready to take photos. I've desoldered Q1 2SA937 and tested the PCB after. I connect PPU pin 21 directly to TV, bypassing the video mod circuit part. Still nothing is shown. As mentioned before the famicom has been modified before, with channel 1/2 switch removed. Sound output from cart pin 46 is working. Start and reset button are working, as I test it with a game. I decide to use a prototype board for the mod circuits. I've attached some photos. Please see and advise what cause the no video output even directly from PPU pin 21. I don't want to declare the PCB had been faulty, at least not yet. Thanks!
that's a clone machine , right? :question:
the shell looks original though ???
Quote from: 80sFREAK on January 04, 2013, 02:01:44 am
Quote from: Alboma on January 03, 2013, 06:41:07 pmfamicom
EPIC FAIL!
Based on the chips and the PCB? If yes then thanks for the productive response. Then I can stop wasting time on it. I can always look for another famicom on eBay, but yes it's getting rare. Only this time I will find a AV mod directly.
Post Merge: January 04, 2013, 11:39:54 am
Quote from: keropi on January 04, 2013, 03:12:05 am
that's a clone machine , right? :question:
the shell looks original though ???
Actually I got the machine from a eBay seller. It came with original packaging and instruction manual. As said before the machine had already been modified by someone. You can see from the picture that I needed to tear off the sticker on a screw in order to open the case. From the photos pls see if it's cloned or not.
But never mind that. It looks like I will not get any positive response here. In fact I'm not coming back here. Peace out.
What a cheeky eBay seller!
So I just performed the new AV mod on my Famicom after having done the mod that was listed on http://jpx72.detailne.sk/modd_files/fc/avmod.htm around a year ago. I saw it had been updated, and I always had faint jailbars. I decided to do the new mod, and to my surprise the jailbars got much much worse. They are dark black vertical bars. Additionally I now have diagonal bars.
I haven't added the foil, but currently I have lifted pin 21, and followed the guide otherwise. I seemed to have the most luck last time with a 1000 uF cap between two points on the PPU, but I forget what those two points are. Any other suggestions for reducing the jailbars? I certainly didn't expect them to get worse.
I read some illusion to adding more caps along the power rails, and this thread would provide more specifics, but I haven't seen the specifics.
Post Merge: January 22, 2013, 08:00:19 am
so I added 12 0.1uf Caps between as many exposed 5V lines as I could fine. This reduced it quite a bit. I'll try the copper tape later. I've noticed some games look worse than others. My FDS games look nearly as clean as a toaster NES.
Warm greetings from Soviet Russia to everyone!
This is about GPM-02 famicom revision, for others there might be some differences.
Anyways you always should double check all actions.
I want to tell another success story of famicom console av modding.
I used the instruction from http://jpx72.detailne.sk/modd_files/fc/avmod.htm (http://jpx72.detailne.sk/modd_files/fc/avmod.htm) as a start.
At first I made it exactly as it was said(except step 6 and 7), and I had a jailbars problem.
Also, at that time I did not understand the step 7 at all. Well, this may be because I am not good at English, also in technical terminology.
The next step was to place capacitor between 22 and 40 legs of PPU. This would make the jailbars more thin but they was still there.
Then I followed instruction from http://www.famicomworld.com/forum/index.php?topic=8080.0 (http://www.famicomworld.com/forum/index.php?topic=8080.0)
I wanted to make a shield, but did not got the instruments to solder PPU correctly, so I found that PPU has some distance from the board, where the shield can be placed. Then I got some copper foil(had to detach some from the textolite board) glued it to the paper sheet and pushed under the PPU.
For easy shield insertion I had to remove capacitor C44 from board, then I soldered it back in place from the other side of the board.
After that I have detached the 21 pin of the PPU from the board. Then I moved the scheme from the bottom of the board to the upper part and attached it as on the photo.
Also I moved the 0,1uF capacitor to the position which 80sFREAK suggests. I think it does not change anything just the GND contact is closer.
After this operations I notice some jailbars improvements. They were more sharp before, now they became more soft.
The last step was to put some additional capacitors on the other side of the board. The main graphic improvement have made the red colored capacitor, the others make it slightly better. I suppose the two or three would be enough for my system, but I put 7 of them on every chip power line except the PPU.
This makes the image quality 99% perfect.
I have attached photos of my work. I suggest Guests should register and sign up to see them.
My thanks to 80sFREAK and jpx72.
hey vlade-1, I actually made the same things :)
http://www.famicomworld.com/forum/index.php?topic=4713.msg117161#msg117161
http://www.famicomworld.com/forum/index.php?topic=4713.msg112179#msg112179
80sFREAK, so you recommend move video cable shield directly to pin 20? And remove 220uF SMD capacitors from those two small chips near joy connectors, and add one to +5V of the amplifier? I will try those.
famifan, as I understand in your mod the shield was the final thing which make no jailbar video output?
In my case only one additional capacitor which I mark as red, takes jailbars away, but the PPU was already shielded. Going to experiment more to check the 80sFREAK hints.
Hi, I'm new to the forums here please be gentle! :-[ I'm currently working on my first AV mod and I'm having some difficulties. i have attached a picture of what I have done so far, I'm working on a rev 07 fami and I'm not getting any video output at all. I have tested the transistor and confirmed it is still working and i have triple checked all of the solder points and still no dice :( i have tried to follow the 80s freak guide as best i could and tried to avoid making any stupid mistakes. I appreciate any help or advice i can get from anyone here, thanks in advance!
Cheers
Mushroomsamba
Hello mushroomsamba, from what I can see, you are trying to take power to your video amplifier from 22 pin.
the 1uF is connecting 22 and 20 pins.
And video signal "lives" in 21 pin.
And the power should be taken from any closest spot on the board.
From your photo I can see you connected R150 to 22 pin.
Look at the http://jpx72.detailne.sk/modd_files/fc/avmod.htm (http://jpx72.detailne.sk/modd_files/fc/avmod.htm) for example of where +5 can be found for your board revision.
Thanks for the feedback, so if i understand correctly I should connect the 150R to 5 volts from the other source marked in the tutorial instead of pin 22?
Thanks again
-mushroom samba
Was this page mentioned?
http://vaot.mydns.jp/fc/fcav.htm
In need of translation :)
I have made some tests recently.
My purpose was to check which way is better to get rid of jailbars.
I have already read here some arguments about jailbars and there dependence on TV or cartridge.
Also I have read some opinion that there is no way to get rid of the jailbars at all, because the PPU generates them.
I already wrote about my famicom and soldering some posts earlier.
The reason why I started this test was the video converter, which I used to play famicom on monitor with vga input. While on TV there are no jailbars at all, the converter shows strong jailbars, depends on the game and color. The most bad are in super mario.
At first I thought that this converter is bad. But DVD-player or super famicom shown with no jailbars. So I thought that I need to improve my famicom by soldering something.
So here are the tests. I have checked different video amplifier schemes I have found on the Internet. I have tried to shield the PPU with more solid copper foil and nothing changed. While checking video amplifiers I did figure that jpx72 manual(which based on freak 80's work) shows the simpliest and best amplifier.
At last I removed all modding from the board. And also removed the shield from the PPU.
Then I left only the video amplifier from jpx72 manual, which connected directly to the pin21 which was already removed from board.
No shields nor additional capacitors. After that the image was in terrible jailbars. The jailbars were fat. Something like 20 jailbars over the screen.
Then I added one tantalum capacitor 220uF to the power of video amplifier. And I got the picture which I have begin with when I have got copper screen at PPU and lots of capacitor at power lines. The jailbars are thin looks like they are one pixel wide. So there are like 150 jailbars or smth like this.
I also tried this on the revision 2 of famicom(mine was gpm2) and everything repeated.
So in conclusion I may say that there is no need of additional capacitors on board, but only on video amplifier power. The shielding without desoldering the PPU does nothing.
Later I will try to check more about PPU shielding and desoldering.
By the way I did use the EverdriveN8 cart for testing and some other carts with large chips and with small ones. The jailbars did not changed, only difference in which game it was.
Quote from: jpx72 on January 05, 2014, 01:58:11 am
Was this page mentioned?
http://vaot.mydns.jp/fc/fcav.htm
In need of translation :)
omg! i really do want 'made in japan' ruler as on the pics :crazy:
Quote from: jpx72 on January 14, 2014, 06:51:17 am
But the one thing I didn't was cutting the pin 21 (video) from the main PCB.
ouch! i think it was already known to everyone. Did you ask for help/advice here? or it's just me, am i missed something?
Post Merge: January 14, 2014, 07:07:47 am
QuoteThis for GPM-02 revision, but others looks almost the same. Notice, that hole for pin21 is empty - pin lifted.
Next stop is remove EMI from surrounding traces on PCB. By some reasons capacitance between pin 21 and others quite big and also producing "jailbars".
> Quote from: GohanX on 2012-07-12, 20:26:16
> I would add lifting/cutting the composite video pin, that made the biggest difference in eliminating jailbars on my system.
Only explanation for this is aging material of PCB or either bad layout of PCB.
from that thread
Hello everybody!
New to famicom modding. My life with nintendo systems started at beginning of 90s, with pal toaster nes.
Now little nostalgia trip has emerged, with buying megadrive 1&2, megacd, 32x, almost all the games to 32x, pal toaster nes (with cic mod), D99 famiclone, AV famicom and now latest normal famicom (007 revision board, year 1984 printed on it).
I'm not in anyway pro with electronics, but small mods I can do. So first one was to get famicom to output same quality picture as AV famicom. I used this, because it is so simple:
http://nfggames.com/forum2/index.php?topic=4055.0
After i did that, i took sound from 46 pin. And put 3.5mm stereo jack to the famicom. Started rockman 3, nice image, clear audio. But with smb3, yeloow and cyan colors were absent. They were just white! So added a 47 uF capacitor to the video output between resistor and wire to the 3.5mm. Amazing, super colors after that!
Heres a brief video of my mod:
http://www.youtube.com/watch?v=9I9F4owbgRY&feature=youtu.be (http://www.youtube.com/watch?v=9I9F4owbgRY&feature=youtu.be)
And playing:
http://www.youtube.com/watch?v=jGCRJD2wKdY (http://www.youtube.com/watch?v=jGCRJD2wKdY)
Only gripe is the jailbars. They are not there with AV famicom, but they are there with the modded famicom. They are not bad, but if a simple fix (more capacitors to the board) can eliminate them, i will be all ears :)
Post Merge: February 23, 2014, 02:32:31 am
Crappy easyCAP capture device with winavi. Result very crappy looking video :)
http://www.youtube.com/watch?v=6uJoa8RopPk (http://www.youtube.com/watch?v=6uJoa8RopPk)
Av modded fami vs AV fami. Which is better?
Post Merge: February 24, 2014, 01:21:31 pm
Opened up my D99 Famiclone, It is noac, but the connection to the Video/power board is like the one on famicom, only smaller leads, which got me thinking...Could famicom rf/power board be replaced by that one, and would it work right out og the box...Opinions?
The connector is 5 pin line, like on famicom, it has GND, Vcc, A, VIN, V printed on the Av chip.
I follwed the "new mod" guide on this page: http://jpx72.detailne.sk/modd_files/fc/avmod.htm
I must say, the image quality is top notch, in my opinion. Maybe some slight, slight jailbars, but hardly noticable. I'm happy about the video quality.
My question is regarding the sound, which wasn't succesful at all. There is a buzzing / humming sound, and clearly it reacts to the image. ("black" screen has another frequency of humming than "blue" screen, so to speak). I used shielded cable, and grounded the shielding for both audio and video. I added a 220uF electrolytic capacitor as the guide suggested. I have tried different connections. I have tried routing the audio to my tv, my headset and my music centre. They all get the humming sound.
I live in Europe, and therefore I use a stepdown converter to power the beast.
Here you can see (and hear!) an examble: https://www.youtube.com/watch?v=NUR0-VWNgEs
Any suggestions on how to fix the sound?
Are you sure the humming isn't being generated from the mic volume slider on controller #2?
Quote from: ericj on April 11, 2014, 06:29:22 am
Are you sure the humming isn't being generated from the mic volume slider on controller #2?
I tried turning the slider down to the click, and I tried unplugging the player 2 controller. Same results.
Quote from: drwily on April 11, 2014, 06:24:12 am
Any suggestions on how to fix the sound?
i can't hear any humming in sound.
there are only 2 reasons of bad sound:
1) insufficient voltage input (weak PSU) supplied to 7805 voltage regulator. Make sure at least that the supplied voltage from PSU is higher above than 7V under the working condition (i mean the system should be powered up with running game, etc..)
2) spiked noise from PPU/CPU. To fix it you need to add capacitors on power line as they'll act as the power filters. There were pics of how it looks. > http://www.famicomworld.com/forum/index.php?topic=4713.msg112179#msg112179 I'm not sure how much of them really needed, but they probably helps.
Quote from: famifan on April 11, 2014, 08:49:30 am
i can't hear any humming in sound.
Hmm... There IS humming and a high pitch tone throughout. You should be able to hear the humming more clearly in the "silent" parts when there is no music or sound effects.
Quote from: famifan on April 11, 2014, 08:49:30 am
there are only 2 reasons of bad sound:
1) insufficient voltage input (weak PSU) supplied to 7805 voltage regulator. Make sure at least that the supplied voltage from PSU is higher above than 7V under the working condition (i mean the system should be powered up with running game, etc..)
2) spiked noise from PPU/CPU. To fix it you need to add capacitors on power line as they'll act as the power filters. There were pics of how it looks. > http://www.famicomworld.com/forum/index.php?topic=4713.msg112179#msg112179 I'm not sure how much of them really needed, but they probably helps.
Thanks! Those are great advices! I will find a way to check it out.
1) How do I check the voltage input? (What piece of equipment do I need?) And if I find the volts to be insufficient/below 7V, how do I "amp it up"?
2) Do you recommend any specific capacitors (type and capacitance) to be added to the power line?
I'm very sorry if these are trivial questions. This mod is my first real sodder-project in more than 15 years, so I'm a bit n00bish ;D
I am planing to av mod my famicom( once I get it in) and I am getting all my materials together. I got a big box of parts donated to me and I found some metal poly caps that are rated at 1.0uf /100 vcd and its part number is digi-key ECQ-E1105KF. I was planing to use them to use in step 4 of http://jpx72.detailne.sk/modd_files/fc/avmod.htm . So my question is are they comparable at all or should I just go and buy some actual ceramic caps.
Quote from: drwily on April 11, 2014, 06:24:12 am
I follwed the "new mod" guide on this page: http://jpx72.detailne.sk/modd_files/fc/avmod.htm
I must say, the image quality is top notch, in my opinion. Maybe some slight, slight jailbars, but hardly noticable. I'm happy about the video quality.
My question is regarding the sound, which wasn't succesful at all. There is a buzzing / humming sound, and clearly it reacts to the image. ("black" screen has another frequency of humming than "blue" screen, so to speak). I used shielded cable, and grounded the shielding for both audio and video. I added a 220uF electrolytic capacitor as the guide suggested. I have tried different connections. I have tried routing the audio to my tv, my headset and my music centre. They all get the humming sound.
I live in Europe, and therefore I use a stepdown converter to power the beast.
Here you can see (and hear!) an examble: https://www.youtube.com/watch?v=NUR0-VWNgEs
Any suggestions on how to fix the sound?
Basically, that's how it is on a famicom. I have been working a bit on trying to find a solution for this problem too. It seems more common on the newer model famicom revisions (with FF logo on the front). But basically, the sound inside the famicom go all around and disturbances are picked up from the PPU or CPU.
There could be some trick similar to the pin 21 lift that fixes jailbars. I don't think that adding a bunch of caps everywhere will improve the sound. (we have done some testing) It also isn't because of the power supply.
But I seriously don't think the sound is a major problem the way it is in your video, it doesn't affects the experience of playing. Playing a 30 year old machine isn't like playing a HDMI machine on a HD TV.
Hello!
Maybe someone can help me with advice.
I got Famicom with AV mod, but it have jailbars problem and I want to solve it.
(http://i.imgur.com/XojC3ow.jpg)
Here is the photo of famicom:
(http://i.imgur.com/BojoTC9.jpg)
Motherboard revision is HVC-CPU-GPM-02.
In the lower right corner - this is just LED, not part of AV mod.
seems the board was modded using the method in this guide
http://jpx72.detailne.sk/modd_files/fc/avmod.htm
i would isolate pin 21 (see step #2) by cutting the leg on the other side of the board as close to the board as you can and solder yellow wire directly onto the isolated leg.
perhaps the trace wasn't cut completely and that is why the jailbars are so prominent.
Hi, I'm very new to modding. I'm currently giving the Famicom AV mod my best shot, following the guide on this site, http://jpx72.detailne.sk/modd_files/fc/avmod.htm (http://jpx72.detailne.sk/modd_files/fc/avmod.htm)
I have some questions I hope someone can help me with.
Progress thus far:
In desoldering the Q1 transistor, I broke the middle leg off, so I had to reorder a new one. In the meantime, I believe I've built the rest of the circuit so that I just need to solder in that transistor once it arrives. I also desoldered the Ch 1/2 switch to make space for the video out rca jack.
I'm also waiting on some 1uF ceramic capacitors, so I haven't added those between pins 20 and 22 of the PPU or pins 40 and GND of the CPU.
I also haven't run the audio cable with the 220uF resistor from pin 46 yet as I have a question about that.
I was originally following this guide http://www.assemblergames.com/forums/showthread.php?49263-GUIDE-AV-mod-your-Famicom (http://www.assemblergames.com/forums/showthread.php?49263-GUIDE-AV-mod-your-Famicom) in which he routes the video to the original RF jack and then the audio to the new RCA jack. (I changed guides after realizing that I had a newer revision of the Famicom, the HVC-CPU-GPM-02)
In the new guide that I'm following, it says "The negative pin of the 33uF capacitor is your composite video output! So solder a wire here, that will go to the middle tip of your video cinch." In my picture, I have the blue wire running from the negative of the 33uF capacitor, but...am I supposed to be installing TWO new RCA jacks, one for video AND one for audio (as opposed to somehow using the old RF jack for video?)
If I do need a 2nd RCA jack, is it ok to simply desolder the old RF jack, cut it off with a diamond cutter, and use that space?
Also, once I have soldered the wires to the RCA jack cinches, do I need to run ground wires from each of them to some point on the board? Isn't the video wire already grounded in the circuit with the Q1 transistor, 100R and 150R resistors, etc to pin 20 of the PPU?
Thanks in advance for your help! :link:
Of course you can use the RF cinch for video or audio, just cut the trace that goes to the middle pin and solder your wire there. Ground is already there, no need to run it from other place.
BTW I see you don't use shielded wires (a wire composed of a 1.metal wire, then a 2.plastic cover, 3.metal shielding and 4.another plastic cover). All the interferences that are produced on the PCB can easily affect your wire and create jailbars or other interferences, no matter how awesome you make your mod. Don't underestimate this, use shielded cables instead.
Thanks for your quick reply.
When you say to cut cut the trace to the middle pin and solder my wire there, I'm assuming you mean on the bottom side of the PCB? It looks like all the of pins are soldered in one big glob. (Picture attached) Would I need to suck that solder off and then cut a trace? Could I also desolder that pin and lift it up (like with pin 21 of the PPU) and solder the audio or video cable to that?
As for the wire, thank you for your advice about shielded cables. Would you mind linking me to exactly the type you would recommend? I live in Japan and its actually much more difficult than you'd expect to find specific types of cables. Speaking Japanese doesn't always help because they often use generic terms like "speaker cable" to refer to a large range of different wiring. If I had a link with a nice image, I can at least search around online until I find a matching image. That's mostly what I've been doing to learn all these new terms like "capacitor", "resistor", "transistor" etc, In Japanese, haha. :link:
Quote from: 80sFREAK on September 02, 2014, 05:03:03 am
Quotefollowing the guide on this site, http://jpx72.detailne.sk/modd_files/fc/avmod.htm
I don't think so.
#1 Any low power silicon PNP transistor will do the job.
#2 Do not avoid shields
#3 Keep wires as short as possible
#4 Take ground from pin20 PPU. Don't ask why, just do it.
#5 An AV cable from secondhand shop will do the job. Hint - use PS1 cables, they are long and have good shelding. Last time i bought them for about 100yen each. If you need thin multicore wires, get LPT cable - they are obsolete now, so in junk bins of secondhand shop you can find one for 100yen.
#6 RCA sockets are nice, but... wire cables directly.
#1 I didn't have any other transistors lying around, so I had to order some. I was able to find the 2SA937 ones really cheap, so I got some of those.
#2 I wasn't avoiding shielding on purpose. I didn't know I was using incorrect wiring until jpx72 said so.
#3 The wires are definitely shorter than mine in jpx72s site, but he didn't include the 150R resistor in his circuit. I thought my location of the 33uF capacitor was best in order to keep the 150R wire short. (I assume it's not ok to have it siting on top of the PPU?) And as I mentioned, I'm very new to all of this, so I'm not skilled at all with getting super short connections soldered beautifully.
#4 The black cable is/was to be my ground wire to the transistor. And unless I'm mistaken, it currently is soldered to pin20.
#5 I can get AV cables easily for sure. I'll try to get the ps1 cables if possible. Thanks for that advice!! I only need the shielded cable for the video and audio wires, right? Or should I use them for the ground to pin 20 as well?
#6 I'll wire one of the cables to the original RFs pin on the bottom of the PCB like you've recommended, but I have no choice but to solder the other one to the cinch of the new RCA jack, correct? :link:
Quote from: TwentyOne on August 31, 2014, 02:57:00 am
Hello!
Maybe someone can help me with advice.
I got Famicom with AV mod, but it have jailbars problem and I want to solve it.
(...)
Motherboard revision is HVC-CPU-GPM-02.
Here's another quick and easy solution, after http://vaot.mydns.jp/fc/noise5.htm (http://vaot.mydns.jp/fc/noise5.htm).
The basic idea is to increase the capacitance of the decoupling capacitors wherever seems relevant, so you can either change the capacitors for higher valued ones, or add other capacitors in parallel.
I opted for the latter, adding a total of 9 x 2.2uf SMD capacitors to the spots circled in red.
(http://i.imgur.com/0K6EDGy.jpg)
Here are a couple of close-ups. You'll see there are still a few jailbars afterwards, but they're a lot less noticeable. These pics are taken from very close, on a monitor that is very sensitive to jailbars.
They're also basically completely gone in every plain color but brown (which is why I used this color for the sample pics).
Before:
(http://i.imgur.com/Bd41anJ.jpg)
After:
(http://i.imgur.com/UJauezb.jpg)
I recently did the mod again but I didn't have a 220uF capacitor to solder between pin 46 and audio jack so I used a 820uF one and I have to say that it works even better with the sounds / noise reduction. ;)
Purchased pre-modded Famicom(BAD IDEA) and the picture quality is terrible. Classic jail bars and some sort of interference like watching antenna tv with bad reception. Any suggestions for improvement would be greatly appreciated. board revision is hvc-cpu-07
http://imgur.com/IoX0XAE,YdCIzwp#0 (http://imgur.com/IoX0XAE,YdCIzwp#0)
http://imgur.com/IoX0XAE,YdCIzwp#1 (http://imgur.com/IoX0XAE,YdCIzwp#1)
I bet pin 21 of the ppu is not even lifted,does RF work on it?
I Wouldn't know. Don't have what I need to test. I've already went a head and lifted pin 21 as well as removed the transistor from the board which did clear up the jailbars however the interference still remains.
I would take the yellow wire that's connected to video and solder that to the lifted pin and see if that gets rid of the interference.
I already did that after I lifted the pin.
I also thought that it could be the added circuit, I haven't found any schematics that match it, so I built the one from the link below onto a breadboard, and swapped the circuits temporarily . This produced the exact same results. at that point the only difference between my setup and the one in the link is step 4, which I couldn't do because I have no clue where the needed connections are for this particular revision mainboard. at this point I'm out of ideas.
http://jpx72.detailne.sk/modd_files/fc/avmod.htm
I got a famicom in today for repair. Customer used AC/DC wall wart with reverse polarity. I do a lot of USA top loader AV mods so have lots of those amps on hand. So I lifted pin21 on PPU and connected amp. I was getting only B&W image.
I recall someone saying in another old post that this happens with a bad crystal. Famicom and NES use same freq of crystal so I replaced it with one from my parts bin. I got nice clean video with no jail bars.
Which makes me come to my question: if the PPU between NES and famicom puts out the same NTSC signal then why not use the same amp? Hundreds of people have successfully used the nesdev forum top loader amp schematics (which look different from the ones found here) with 0 jail bars.
I'm not as experienced with famicom as I am with NES and was just wondering.
You can use whatever amp you like.
Just finished my mod according to this sketch. The board is HVC-CPU-GPM-02D. I can see slight bars only in SMB sky.
Quote from: 80sFREAK on April 12, 2012, 04:36:03 pm
(http://longhornengineer.com/wp-content/uploads/2011/07/Image-92.jpg)
I don't know if this was confirmed here, but I can say that Famicoms with the PPU that has a metal plate/heatsink on top gives out lots of jailbars, even if you isolate pin 21 and put the caps on the underside of the board. I've done 3 Famicoms with this type of PPU and they all had this problem. Every other one I have done had good quality video with just faint jailbars on light colored backgrounds only.
My experience preffers the GPMs (with metal shielding on cartridge connector). I was able to de-jailbar every GPM so far really nicely.
Last year I modded 2 Famicom systems to add AV support. One of them was a Hong Kong special where it was modified to be PAL back in the day. Given these systems are now in North America, I undid a lot of the PAL conversion back to standard NTSC.
I was surprised to find that the stock famicom had jailbars, while the Hong Kong special was 100% jailbar free. The only difference is the power side. The modified version used a 3rd party power board with a lot less components. I believe the only way to rid of jailbars forever is to create a new PCB with redesigned power and audio amp. This is similar to what Tim W did for the NESRGB Famicom kit.
What is the best replacement for 2SA937?
Can I use A733?
What is the most recent and best schematic for AV mod?
Quote from: Farid on January 04, 2017, 04:14:59 am
What is the best replacement for 2SA937?
Can I use A733?
any general purpose PNP transistor will work like a charm. there's no specific requirements from that part of scheme.
thus, a733 is perfectly fine.
why are you asking?
at least, the jailbars don't depend on transistor model anyway.
I have been trying to make sense of this page : http://vaot.mydns.jp/fc/noise4.htm for advanced jailbar removal on an HVC-CPU-07. It seems to be telling me to do three things. First, to lift the pin of either the CPU or the base pin of the Q3 transistor out of its hole. I would prefer to do the latter rather than cut or risk destroying a PPU pin.
Second, add extra capacitors, 2.2uF, on the underside of the board wherever you can find an area where there is are a pair of conveniently located solder points between the voltage and ground planes. I think he scrapes up some of the planes to solder the capacitors, but I don't believe that will be necessary.
Third, he adds a 330uF/16v Conductive Polymer Aluminum Solid capacitor between the ground pin of the PPU and a nearby spot on the voltage plane. I believe the ground plane goes to the negative lead of the capacitor, which is marked by a purple semicircle on top of the capacitor.
Is there anything else to be noted? Do I have this right?
THIS. (http://vaot.mydns.jp/fc/surround.htm) For those, who want to try pseudo stereo.
Did anyone have ANY success reducing jailbars on HVC-CPU-07 board with RP2A03E + RP2C02E?? At this point I have tried everything, soldering OS-CON 330uF 16V between PPU 5V and GND, installing 4x 220uF capacitors between PPU 5V and GND, installing many ceramic 2.2uF caps in all possible places and I had NO improvement whatsoever... First of all, yes I have lifted pin #21 PPU and base of Q1 transistor and connected them directly and even after that I don't think the picture improved in any way. Those jailbars are so noticeable and I think the only solution is to live with them, I have spent hours and hours to make it look better but it's so stubborn the picture just refuses to look clean...
hello, im new to the forums.
as i travel from time to time to japan i have frequent ocasion to buy original famicoms, naturally i wanted to start av moding i followed the guide on jpx72's blog site but i have some questions, sorry if the answer is here but reading thru 22 pages of posts is quite challenging:)
1. i cant seem to find 33uf ceramic capacitor, the owner of my local electronic shops says they dont make ceramics ones of that value, so my question: is there a mistake of suggesting ceramic one or a mistake in value?
2. the same issue for 1uf ceramic capacitor, maybe mistake in value on the blog?
3. can i desolder and remove the RF output cinch completely? do i have to bridge something on the rf board to do that? or should i not touch it and just put a pair or another cinch ports next to it? for video and audio