I'm working on a Bally Rolling Stones with a sound issue. The problem is that the board will only emit those annoying fake chime noises and not any of the proper tunes & sounds that everyone knows and loves from the -51 sound board.
Yes, switch 29 and 30 on the MPU are both "on". This board was working fine for a year and then one day it started producing only the chime sounds. Last year, I replaced the pots, caps, sockets and headers. Today I swapped out the rom, 6810, PIA, processor and sound generator. I've reflowed the solder on the headers for good measure. I tested the board in another game and the problem persists.
Pressing the test switch on the -51 produces the "tune" I would expect, so it leads me to believe that the board is just not understanding that switches 29 and 30 on the MPU are on. What part of the sound board determines what type of sounds to produce?
Your help would be greatly appreciated. Thanks in advance.