Quoted from TZ:
So I think I have made some progress following the steps in the Pinwiki for WPC resets (as suggested by LTG).
Only played a handful of games so far but....
A) Replaced J101 connector and pins to try and increase voltage at TP2. Removed the IDC connector and went to the trifuricon pins (very difficult with the double wires). Unfortunately this had no affect, voltage remained at 5.00VDC
B) Only replaced pins at J114 connector. I would like to replace that IDC connector too, but think it would best to replace the Z connector at the same time and will do that when I have time. Just replacing the pins on the board helped with the voltage drop between the driver board and the MPU board. I was seeing 4.90VDC on the MPU (at pin 32), now I'm seeing 4.98VDC.
Thanks for all of your suggestions!
I was having reset problems, too, and this also seemed to have the greatest impact on my game.
Re-seating connectors worked as a temporary fix, showing it was a connection issue. The board and pins are fairly new (Rottendog), but I replaced J114 from IDC to Molex trifurcon and the results were immediate and, so far, permanent.