Quoted from RGarriott:

Solved.
Connectors connectors connectors on these Gottliebs. Went back and cleaned the connectors and wiggled the wires and boom we have sound again.
Hey guys got a question. I had a cr2025 battery button installed but seems to loose high scores after about a wk or so of not turning the game on. I had a extra weebly 5101 nvram so I decided to install it. Once the old chip was taken out verified all traces were good, everything looks good. Installed the nvram game turns on everything is good except the sound. I lost my sounds. Game plays normal and also saves scores with the old battery taken but no sounds.
Anyone got an idea?