Well, good news. I'm up and running without having to send my system out. As I was looking the pcb over, the caps looked good, so I kept dialing on the pots... and they weren't the issue, either. I started to watch the laser carriage closely while powered on so I could see exactly what was happening when the audio cut. It wasn't moving at all at that point, and jarring the system was causing the laser to reset, and then I'd be back on for a bit. After testing and prodding about, I re-soldered the wires to the motor that turns the gears that move the laser along the assembly. Bam, I'm back in action. Played for about 2 and a half hours, and no faults, playing Gradius II, R-Type Complete, Gate of Thunder, L-Dis, and Super Darius. I think I found my issue finally! Something so easy, but just not the usual culprit for these sorts of issues.