I'm working on a Bally Black Belt where the background sound cuts out intermittently mid-game. It's weird, the background sounds will work fine, then cut out--but the sounds made by hitting targets etc still work. Then on the next ball, background sound is back...and eventually cuts out sooner or later. I replaced the 4 commonly-replaced electrolytic caps from a kit purchased from Marco. I reflowed the solder on the header pins and re-pinned the female connectors. Seemed to improve for a bit, but it's still doing it. Any ideas?

Edit: i also changed the potentiometer on the coin door and the pot VR1 on the sound board

You know, i just realized i forgot to mention that i changed the little pot on the board, vr1. There was an issue with the old one. I'll try turning the new one back and forth a few times and recheck all my work on the board just to be sure. Thanks!

Haha forgot that one too, coin door pot has also been replaced. My next move is to replace the male header pins. I was also reading about a freeze-spray method where you blow it at the various chips to see if hitting a particular one gets the sounds working properly... Gonna have to try that too.

Awesome, thanks for the tips! I'll give it another shot!