sure sounds like software is corrupt or power supply is still bad, no ac riding on the 5 volt power supply, should be less then 10 mv ac, did you install the new software on the original board? if so maybe the board corrupted the software at that time and is the reason it would not function on a new board. is 12 volt power supply good? if you had another car to experiment with, try moving your software from vertex to a good car. I am not sure, would have to check, but isn't M0 a RAM chip, are you moving it along with the eproms that go in M1, M2 etc. maybe the Ram chip is bad. did vertex send you a chip that would go in the m0 slot, the older boards had a removable m0 chip, that had a tag like the eproms on top of it, the newer boards have m0 soldered in place and hence non removable.