Sydney
Quoted from MikeS:thanks. It's a brand new power supply board (Gulf Pinball) and voltages were all in spec before i added the MPU which is why I suspected that as the potential issue since it's the only variable that's changed. .
the Gulf Pinball power supply has a heat sink on it that sticks out further than the standard power supply, and if you used the original Power supply brackets it may be earthing out on the metal in the backbox
try playing a game with the backbox opened and see if it happens again
Nashville, TN
