I have a client machine (Stern Lightning) I've been working on that suffered a display high voltage short on the lower body power board, the 200 volt display pin shorted out and burned a hole through the board and arced across the neighboring pins. I offered to buy the machine from her knowing that it was going to be an expensive repair but she agreed to my estimated repair costs. The short damaged the Power / Solenoid board which I repaired and damaged the MPU which was replaced along with the lower body power board.
When I first booted the machine with the new MPU everything worked without issue however the voices were present but distorted and after a short time the voices got progressively worse and they are pretty much long static patterns now. Sound pitch is present when the board is triggered and works as expected according to game action so I assume the voice chip is working. U10 was generating excessive heat on the right side and removal did not improve the issue. I have removed both U9 and U10 to silence the VSU-100 for the time being and the machine is working and playing sans voices after a 10+ year sleep.
My client is so happy to have the machine back and running in its current playing condition that the missing voices aren't much of an issue for her but wouldn't mind having the voices working if the cost is reasonable considering she has spent quite a bit on me getting this machine back up and running. After a bit of internet searching I have not found any source for the sound Roms so figured I'd ping the forum to see if I can find any sources.