I'm helping a friend troubleshoot his Black Knight LE pinball machine. It randomly resets during game play. The 40 pin interconnect has been replaced. We have socketed all the eproms and processor and replaced around half of the chips on the board. We repaired some broken wires on the right and left flipper solenoids. I'm just not sure if it's a logic issue or a power supply issue. Any inputs would be greatly appreciated!!

Thank you!

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Barakandl, thanks for the reply. Yeah, the reset is totally random. I have even just let the machine sit and it will reset. I started a game and didn't shoot the ball, just let it sit there and it would reset. Sometimes it takes a long time, sometimes it doesn't do it and we can play it for a long time.

I will check the 5vdc line. I don't have an o-scope to see the ripple on the 12V line. I will verify the flipper diodes too.

Thank you for the advice, it's what I need at this point.

Great info!! Thank you again. I'm going to head over to my friends house on Tuesday to work on the machine some more. I will check these things out and will report back. I can't thank you enough for your advice.