Hello, I'm trying to repair this jamma pcb. The game works but the sound not: there is a repeating sound that goes on and on. I checked all the audio section from z80, 2 ROMs, 1ram, 2 Yamaha ym3812 and ym2203, 2 DAC, 2 opamps, audio amplifier obviously works because I can hear sounds, 2 m5205.
Then started to check the signals starting from z80: clock and interrupts are ok but many address and data lines are high or low. Then I found that ROM ce is low and that's where I'm focusing.
If someone has some hints or could point me to a similar configuration scheme it would be highly appreciated. Thanks