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No problem, that's what it's supposed to do. Pressing the switch generates a special interrupt to the sound processor, where it goes into an endless loop playing a single sound effect. This verifies functionality of the processor, ROM, PIA, DAC, amp, and speakers. Not sure if it ever changed, but on mine it plays the "thump" sound btw.Just got a new sound board from quarterarcade. When I push the diagnostics button, a sound repeats...
The data path you're testing now is CPU board -> ROM board PIA -> sound board PIA. Do your coin door switches work (e.g. test mode / advance)? Those go through the ROM board PIA also, so would be a quick way to check its functionality. The most obvious point of failure though would be the sound select wiring/connectors between the ROM and sound boards (header 2J4 on the ROM board, IOJ3 on the sound board).Thanks for the reply,
I should have posted the whole description. If I don't press the diagnostics button, I get no sound when the game is up. I have new connectors on all my cables and the sound board was purchased in working condition.
Something on the ROM board maybe?
Just to confirm, did you do this on the sound board or the ROM board? It would be helpful to rule out the entire wiring/connector path by doing this on the test points of the ROM board (the test points are the 7 circular solder blobs right next to the connector). Your other data looks normal; pin 8 is left disconnected as a sound select on Joust.Thanks again for the reply. So grounding the sound select yields pins 2-7 working, pin 8 produces no sound. Trace back to ROM board next?