OP

Quoted from QuickDraw:

I had an issue that i posted about a long time ago, i can no longer post in that thread but the issue has progressed: https://pinside.com/pinball/forum/topic/black-knight-problems-3
basically i had an intermittent issues with the game locking up randomly, which with help i determined it was something to do with the flippers, when i would activate the flippers sometimes i would get a lockup. I sent the driver board and MPU out for a refresh which they did all of the bulletproofing anf replacing interconnects. When i got the boards back the issue persisted. it was suggested that i replace the flipper diodes which i did with 1N4007 diodes. after replacing the diodes the issue seemed to get worse. now it locks up usually within the first 3 flips of the left flipper. I checked the diodes to make sure i had them installed with the band towards the thick wire on the flipper coil and re-replaced the diodes on the left flippers which had no effect on the issue.