having an intermittent Transistor fault on an mrvf car. the mechanics have already swapped out all the transistor units, all the control boards, the backplane rack that the boards plug into. the ribbon cable that connects the transistor boards to the backplane board. I went out there a couple of weeks ago, and the car would fault every run, probably ran it 20 times . i removed the connector on two of the boards that connect the flyback diodes to check if they were ok, all was good, so i tried to run it again, and it ran fine. it has run for two weeks now, and started again on friday with the transistor faults. the mechanic has reseated the connectors again, but this time it faults continuously. any ideas,