Quoted from zacaj:
That's a cap for the displays, I don't think it'd affect the sound.
Last time I wired a cap like that backwards it exploded...
If, once you replace the cap, you get your HV levels correctly, I'd assume you're fine.
Got the board back today. One of the fuses on the power board was blown, but after replacing it - displays came back just fine.
Still not getting any audio though. I get a hum from the speaker, and it crackles a bit as you turn the volume up and down, but I get no game sounds. When the game is on but in game over state, pressing the little audio test button doesn't get any test audio. The hum seems louder, but no sine wave or whatever sound it's supposed to generate.
There's a second (red) toggle switch - marked "sw2" on the schematic. I hate to say this, but I honestly have no idea what it does. It's in the same position as it had been when the game was working pre re-capping though.
I pulled and tested both fuses for the board and they're fine. I've made sure all three connectors are tight and snug multiple times. My friend's soldering work looks all fine to me. Any ideas on what to look for or check?
EDIT: Got it working. Not even 100% sure what it was, but I pulled the board back out. Jiggled each wire on each of the three connectors slightly - pushed them in as far as I could. And the likely culprit - I pressed all the chips on the board in a little bit. It seemed like one of the chips was out a tiny little bit. Side note - I didn't re-pin all the connectors, nor swap out the chip sockets when bringing the machine back to life. Anyway - back to normal.
PS - of course when I first tested it, the volume happened to be all the way up. Cat status : HIDING SOMEWHER AND APPARENTLY NOT AMUSED.