My brother asked me to post this for him. He's in the process of reviving a Bally "Star Trek" game (original version).
"I have a strange problem with my Bally Star Trek. The game will not boot up if the sound board is connected. I get 6 pulses from the MPU board. On the 5th pulse, I get a blip from the sound board but then nothing. If I disconnect the large connector to the sound board, the game will boot up normally. I can then plug the sound board back in and it works normally. What if anything do I have to replace on the sound board?"
The game has an Alltek replacement MPU board, and he has repinned many, if not all the connectors.

Thanks. I'll pass that information on to my brother.