I bought an abused F-14 Tomcat many months ago and have been slowly restoring her back to her former glory. My final technical issue has to do with the sound. There were no sounds when I bought the machine. I replaced the old capacitors on every board and all of the suspect (burnt/loose) Molex connectors. The sound started working and was working great for a month or so when it abruptly stopped.
Now the sound works great once it decides to start working. The trigger for the sound starting seems to be ball ejector solenoid. After about 10-20 ball ejects the sound will kick in full steam. When there is no sound, pressing the sound circuit reset switch on the MPU will occasionally start the sounds that reside on the MPU, but there will be nothing from the background music board. Restarting the machine will normally result in various high pitched continuous tones, then nothing. During one of my various debug attempts, I lost the explosion sound that comes on during the match routine (sound 15 in test). Even when the sound is working this sound never plays.
I would be grateful for any insight anybody might have this issue.

Bump. Still stuck.