There should be no contactor on when you turn the key on until demand by the travel Or pump lever. The transistors All must be replaced in 3's. Check volts to frame. Is the plastic isolator behind all contactors? Hours on unit? Japan drive or GE motor? Any deviations on a contact coil is to be replaced. If you have a known good cpu I would try and swap them. Sometimes a visible fault Or failure is not there. Flight systems handles rebuilt cards.