Interesting prob, although i can't help thinking it's more to do with power-supply not the mpu board.

While the voltages *might* be correct, i'm sure something is giving out under load, hence the 'weak' flippers...
the 60volts dropping to 20v or something? or the 5v regulation failing and droping to 4v etc....

Is there DEFINATELY 5v on the MPU board, and CPU?

I'd hate you to fork out on a new MPU board only to find it's your power supply that's causing the probs.

MM.