Sega CD model 2 scratchy sound

Funai as in manufactured by Funai Electric co. under SEGA's request. The single board SEGA-CD2 with NEC CDD chip is the Funai board. The official SEGA service manual is the source of that information. The Funai board has no SEGA logos anywhere in it. Which makes sense, too.

 

This is what I have; while I was adding your comments to the pic, I see now a trace that looks suspicious (in red)

 

Also, I had another unit to test with, almost the same but this one was the one that had that add on board glued to the PCB, besides that it looks exactly like mine, I swapped the pickups just to rule that out and the issue stayed with the PCB.

 

Looks like your capacitor leaked and damaged the traces. Check them with a multimeter for broken connections.

 

No bad traces found, so I pulled that chip and while doing that I lifted 1 pad, so when I put it back is not working, I will get to that at some other point, BUT now that the IC is not working the noise went away, so this confirms that this is the problem, everything else works.
Thanks for your sugestions

 

The passage holes can also get bad. You need to look the schematics and check where each pin of the Sanyo chip connects to, elsewhere.

 

I haven't had time to look into this yet because of other project, but I safely put it away and I will revisiting this soon and follow your advice; I have now an oscilloscope to aid me on this but I think continuity testing is all I need to find the problem.