I'm no expert on sound boards but you say sound works with test button but not during game play. And your Spirit board works correctly in Punk. So my first thought would be to look on the schematic and see which chip receives the signals from the MPU to tell the sound board when to make sounds. I would first suspect that chip or the edge connectors leading to it. Just a thought to look at.

Ahhh! That's a whole different story! Then we know your sound board is good. Has to be either the cables and/or molex connectors or the chip on the mpu that initiates the sounds. I think the Spirit MPU will work in the Punk. Switch your rom over and give the Spirit mpu a try in Punk. If you get sound during game play, then you definitely have a problem on Punks mpu. If not, look at connectors. Follow the sounds off the mpu, through the connectors, and to the sound board inputs checking for a loss of continuity along the way.

If you prefer, you could also put the Punk MPU in Spirit and see if Spirit then loses its sound, confirming Punk's mpu has a bad component(s).
PS Spirit is a great game! I have one in my collection and would probably say it is the favorite of all my games!