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Did you resolder those gate resistors, or did I do that? I can't remember now. If I did it, then I must have removed the control board for some reason while I was building the controller. There were a couple control boards that I had removed in the past so as to fix one thing or another. I wonder if your control board had "walking wounded" components on it then. Recently someone told me that after something like a mosfet failure, a voltage spike through the gate resistor or through the source leg can partially damage something like the mosfet driver or the hcpl-4504 optocoupler. I wonder if the driver was only partially functional. I don't remember anything wrong with yours, but the board has been removed (probably by me). 120v shouldn't have been a problem if every 200v component was working as it should.
For all the mosfets to fail in unison is interesting. The only other failure I have seen is with only 1 or 2 mosfets blowing up. Ben's first controller, and Hondo's controller, which had a gate resistor break off from vibration. For them all to fail simultaneously to me means they must have all seen a voltage spike over 200v, or the gates all saw a spike over 30v, or something else weird. Is it possible that B+ and B- leads got reversed on the last time the 120v was hooked up? That would cause a short circuit which would blow them all up at the same time.
I think I have most of the parts to make another one. It would take a few weeks, though. If that's OK, I can get busy, and I'll try to be more careful this time.
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