Quoted from Chalkey:
Regrettably, I sold my beautiful Hook. BUT... now I need to work on one that's having some issues. The game is apparently stopping playing the music randomly and will only play sound effects until another song starts. It will reset during multiball or possibly just periods with a lot of activity. I'm suspicious of 5v, anything else stand out I should be looking at? I know it has older code on it but I doubt anything this unstable was ever code related. Going to look at it later this week.
I mean you did help find the display glitch and get that fixed...so get to it lol
Is it actually playing the startup sound? Or just losing the music?
It could be voltage dropping to the sound board, possibly when something else is happening that draws more power, bad roms, or roms that just need to be reseated. Assuming it's not a more complicated board issue
Basically the CPU is calling sounds from an address in the sound roms, and telling it how long to play them for, which sound has priority, or when to stop on command, like if a mode or song changes, or another target is hit.
The sound/voice effects are just being called before more music starts and/or played overtop of the music. So once it loses data or can't find what it's playing for whatever reason, you get silence until another sound is called. It's not constantly playing it and retrying the whole time, for lack of a better way to put it.
If you hear the startup phrase mixed in...the sound board is actually rebooting.