Not sure what happened either. Here are the details in hope that it may solve another customer's problem.
On power on. it appeared to be trying to move carriage but did not move, Carriage moved freely by hand. No red switched pressed. It only made a pulsing sound. Fan either did not run at all or ran very slow pulsing with the sound made by the carriage stepper motor. No display. When I checked the power supply with normal pwr supply connections, 5V terminal rose to 5v then quickly decayed to zero and continued to do this. All pwr supply terminals were hot glued, but screws were not tight before gluing and positive supply wire to the fan appeared to be shorting out supply. Fix was simply removing and carefully reconnecting supply terminals. Had to restrip and bend fan connection to prevent more shorts. So far so good, three cuts.