Famicom av mod instructions?

[tonev]

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 )

[famiav]

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 ... )

[famifan]

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?

[famiav]

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)

[Pikkon]

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.

[famiav]

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!

[famiav]

Mine is HVC-CPU-07 revision...

[famiav]

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

[famiav]

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 ...

[famiav]

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"

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 !

[famiav]

No problem
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

[famiav]

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 ...

[famiav]

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 ^ ^

[famiav]

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?

[famiav]

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 ...