I have a S&T board that boots all 5 flashes but absolutely no sound at all, no speaker hum nothing. I have a working board so know it’s not the speaker / etc.
I’ve replaced the LM 3900 amps still no luck. Any assistance greatly received. I have a scope but can’t find any guides on what you should see / how to fault these boards. I have also swapped out all the socketed chips into my known working board to prove they are all good