Famicom av mod instructions?

[GAINAX]

Thanks for the help! I'll get to work on that now

[jpx72]

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 

[keropi]

I believe that's an aluminum self-adhesive sheet that is used for rf shielding...

[keropi]

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 ?

[GAINAX]

Well the mod worked in the end Thank you guys again for the help and tutorials!

Now time to play me some Rockman

[GAINAX]

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.



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. I guess it's got to do with my revision of the board: hvc-cpu-08.

Any help would be much appreciated

Edit: Thought I should mention I'm not using any shielded cable right now.

[2A03]

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

[GAINAX]

Not on purpose, just all I had at the time.

[2A03]

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.

[Rosser]

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

[famifan]

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

[80sFREAK]

Looks like it depends on region - capacitors in the TV or not

[MaxWar]

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.

[2A03]

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.

[MaxWar]

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?