CPU may be broken, looking for potential next steps

Started by Pilch Dragon, July 13, 2021, 08:10:10 am

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Pilch Dragon

Hi all,

I posted yesterday regarding a failed AV mod that ended up causing my system to no longer turn on. After doing a bit of research and diagnostics, it seems that my CPU (RP2A03E) might be fried. This is primarily due to the CPU getting really hot really fast, and there not being any video/audio output at all.

The question I would like to ask is this: What options I have going forward? Are there any other potential fixes I can try on the CPU to get it working again? If not, are there any places I could get replacement chips to install into it? Am I just better off getting a new Famicom and not trying the mod again?


If it's broken I don't think there's much you can do but desolder it and replace it with one from a Famicom (or NTSC NES) that is broken for another reason. Alternatively you can use one of those Famiclone CPUs (UA6527, not the UA6527P as it's PAL) you might find on ebay or Aliexpress. Those are clones and not ideal (the APU would sound very different for one thing) but they should technically work with games that works on such clones.

Replacing the CPU would be harder to do than an AV-mod however (it's a bitch to desolder), so picking up a new working Famicom might be the best option.

Pilch Dragon

Thanks for the advice. While it is a little disappointing to hear that there's not much I can try regarding the CPU, I had a feeling that would be the case. I've decided to buy a second famicom with a busted up shell (helps bring the price down a little) and I'll use the main board of that in the shell of the one I have now. While I couldn't find a CPU at a reasonable price at the moment, I'll keep my eyes open for one, since it'd be nice to repair the broken system.


This time when you do the AV MOD, DO NOT remove the original transistor and DO NOT lift the pin 21. Just add the new components according the to scheme.