Quoted from DanMarino:Awesome emsrph,
I removed the SDB J3 and MPU J4 connectors. The pins looked fine, so I shined them up a little with steel wool.
The connectors seemed fine too. Nothing was burnt looking. The wires and connectors seemed snug in the plastic connectors.
I plugged them back in and re-tested the voltage on the MPU TP4 and TP5. It now reads 4.83 volts. So that's a pretty big improvement.
I have played a few games and the missing explosion sounds are now working!
Thank you very much emsrph!
Back in business! But, it may have been temporary because the plating has been removed from the pins and will burn again.