I got a cue ball wizard without sound. both sound boards seem like they might be ok & flash red indicating 5v. Seems that my problem is with the 12v. VR1 on the aux power board is getting supplied with about 17v DC. The output should be 12v, but is about 2.8v. I've already changed the capacitors & I've replaced the voltage regular multiple times using multiple brands. Still only 2.8v output! Clearly I'm missing something. To my untrained eye reading the schematics, I can't understand what else it might be.

Tested diodes already, removed them from the board to get an accurate test. Changed capacitors & voltage regulators already. Same issue. No cracked joints anywhere that I can see

Interesting so if I disconnect the aux sound board, I read 12v at VR1 on the aux power board.
Now I"m starting over trying to figure out what this means. I do have a 7430n on the sound board that might be testing bad but I'm not so sure that would be causing this voltage issue

I actually don't have a jumper on JP5 or JP6. Although according to the schematic I should have one on JP5. Perhaps I should jump it? I have two mc3403 on the aux sound board.
At this point I'm assuming the aux board is the issue since everything 5v related seems fine.

voltage is fine without the aux sound board attached, so the issue is def on that. I ordered a couple mc3403 so I'll try replacing those, fingers crossed! thanks

Still haven't figured this out. But I have noticed that all the hum & noise is from all of my speakers pulling in immediately at game start, after a minute they smell like they are burning up. Like I flick it on & watch the speaker insides suck in all the way. Must be at aux power supply because it still does it with neither sound board connected. I've already replaced the voltage regulators, capacitors, both amps & both large capacitors. I'm about ready to throw in the towel & order a new board, but I also have to be getting close.

Any idea what fault can cause this leak? I've replaced all the notable parts on my aux power supply & it still happens. I did just order a new board since PBR had them cheap enough. Fingers crossed this is the issue or else I'm really at a loss. I checked the grounds as well, everything seems tight & connected, no cracked joints at transformer panel connector.