Need a little help with a famicom AV and a sharp twin famicom

Thought I'd try my hand at repairing famicoms, I thought wrong.

Famicom AV had a dead power pin. Some one tried to fix it before and it was just ... bad. Replaced the pin, cleaned up solder that was all over. Console turns on now, but I only get a grey screen. Its not thew typical "clean cart connector" issue, that I know for sure.

Next is the sharp twin. The console turns on and plays games but the graphics are a mess. Any game you load will result in this, even the fds displays graphics issues. So far it seems someone was trying to mess this up as the bottom of the power/av board had scratches on all the traces right where the vent is.

Any help is appreciated! thanks

 

How do you know it's not the typical cart connector problem with the Famicom AV?

 

I want to say it isnt because there are no cold solder joints and all the pins are clean and are pushed out plenty.

 

Well I'm going to try replacing the ppu on both systems. I'll let you guys know how that works

 

Well wasn't the ppu on either. Maybe the cpu or sram, or 74ls343. Will update.

 

Famicom AV was a dead CPU. ppu was fine. Put 40pin sockets on it since the chips were off anyway. Ill do the sharp twin next after I buy more 40pin sockets.

 

Last post for this thread.

Sharp twin Famicom fixed. Ppu and cpu are fine. Turns out there were two corroded traces under a video ram chip. Repaired the traces and I was set.
Replaced the belt in the FDS portion and cleaned the magnetic head fixed the error 22 I was getting.
Lastly used epoxy to fix some cracks in the controller holder slot.

I hope this post is useful at all to any who come across it.