Sure this isn't for all scenarios, but a fix that could easily go undetected, so figured I'd share.
I had a Sys 11 game that had sound but no music, not in test, gameplay, anything. Anyway, I pulled the Audio board and buzzed everything out, no cracked solder joints, obviously wasn't the amplifiers, everything looked clean and fine. All the ICs were socketed well and no corrosion. Looking closely over the entire board, I noticed the 3.57mhz crystal oscillator at X1 had a leg come off. Being a chicklet like component, it had been bent backwards some and one leg lead had completely come off, but it was hard to see until pushing it back some.
Anyway, new 3.57mhz crystal osciallator from Great Plains for like $1 and 5 minute fix. Sound and music back! Hope this info can maybe help someone else with this problem as somewhere to check.
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