Genesis Model 1 Missing Sounds

[Chomolonzo]

I'm having an unusual issue with my Genesis Model 1, in that some of the music, or rather some of the layers, or instruments, from the music either cuts out or drops to near-silent levels while the other instruments play just fine. Particularly noticeable in Earthworm Jim. Pulled the system apart and had a quick look, but I'm thinking that perhaps the Yamaha sound chip is busted, or could it be bad caps? Haven't been able to find any damaged traces.

Anyone have any idea as to what the problem could be?

[NoAffinity]

Have you recapped recently? Might be worth doing the mega amp or triple bypass while you're in there and just bypass the original audio circuitry altogether.