CPS1 board with missing caps in audio circuit

[xga]

Hi guys. I have a CPS1 89626A-3 (DASH?) board that is missing a few caps in the audio section.

The first missing cap is an SMD at "C22" that looks like it might have vaporised.

The second missing cap at "CC20" I believe is a 10µF 35V tantalum (perhaps it was never populated on this board for some reason?).

Would anyone happen to know the values of the C22 SMD cap, please? I can't see this cap listed in the CPS1 schematics I've found online, so perhaps there aren't any for this board revision?

Cheers

 

[duffcon]

Looks like you have a hacked together audio circuit:

https://www.arcade-projects.com/threads/chinese-hack-forgotten-worlds-conversion-audio-broken.24020/

 

[xga]

Hmmm. I think the pot may have been replaced and the audio circuit recapped, but apart from that, I think it's all original. Original audio amp IC, original 2151, DAC, OKI etc...

 

[xga]

I transplanted caps from a donor board and in the process measured the C22 SMD cap (95nF). It's probably just doing some filtering and not strictly required. Hope this might be useful for someone one day.