AV Famicom: Black screen and loud buzzing

I finally had my NESRGB working in my AV Fami. I was able to successfully boot SMB, then I switched games and it died. All I got was a black screen and a loud buzz. I though I fucked up the NESRGB, but apparently not, because I undid the mod, and still no dice. Any idea what causes this?

daskrabs said:

I finally had my NESRGB working in my AV Fami. I was able to successfully boot SMB, then I switched games and it died. All I got was a black screen and a loud buzz. I though I fucked up the NESRGB, but apparently not, because I undid the mod, and still no dice. Any idea what causes this?

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I usually start by checking if the cpu and ppu are both getting 5v just to make sure the power circuit is working or not. If it is I move onto replacing the CPU and or PPU (most problems I get are usually one of those two things). Check to see if 5 volt is shorted to anywhere it should not be. Make sure no blobs or solder or clippings are shorting pins. You also did not bump the kit loose while it was running did you? The kit being removed while its power on can fry both the CPU and PPU. I had someone send me an AV Famicom they had dropped while it was running (knocked the kit out) and it fried the PPU, CPU, and the video encoder on the RGB kit.

Also try another PSU to make sure it didnt give out.

PSU is fine. Looks like it was at least my CPU. Both chips getting 5V. Bought a parts NES locally, replaced CPU, and the buzzing stopped but still black screen. Tried removing the PPU, and busted a leg completely off. The fun never stops. Thanks for your help Skips.

daskrabs said:

PSU is fine. Looks like it was at least my CPU. Both chips getting 5V. Bought a parts NES locally, replaced CPU, and the buzzing stopped but still black screen. Tried removing the PPU, and busted a leg completely off. The fun never stops. Thanks for your help Skips.

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Check the power and ground pins on the 72 pin connector(first and last pins). Apparently there are a few games that push these up out of place, and when the next game is put in, the NES does nothing because the cart has no power. IIRC you can bend them back down with a pick or a small screwdriver if you're careful.

EDIT: wow I read that quite a few times and replaced Famicom with NES. not sure if it still holds true with the a/v famicoms, but it may be worth checking.

Postmortem: Fried the CPU and PPU. Replaced both and it fired up. I guess Skips' hypothesis was correct. Must've knocked it loose while running.

daskrabs said:

Postmortem: Fried the CPU and PPU. Replaced both and it fired up. I guess Skips' hypothesis was correct. Must've knocked it loose while running.

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Glad you got it going dude Hopefully your RGB kit is fine as well.