Let me get this straight. You discharged the G07 in one game, and the game next to it, plugged in to the same power strip, stopped producing sound.
This really shouldn't happen - the only thing I can think of that might cause this is if somehow you're missing the ground at your wall socket, so the ground pins of both games were connected to each other, but not ground. That could send a "zap" through the ground wire, raising it's voltage suddenly. If the wall socket is proerly grounded, however, this should not be able to happen.
Even then, Ms. Pac's logic board is powered by a transformer, and nowhere on the wiring diagram do I see the external ground connected to the PCB. The only thing I can think of is that the frame of the speaker is grounded. Perhaps you burned out the coil in the speaker with an arc? Unlikely, but it's the only plausible situation I can think of.
-Ian