Thanks for the help, everybody.
Followup. It was the power supply. I had a spare in a CNC control computer I'm not using right now.
METALWORKING CONTENT. Dell's power supply has no switch and the metal case was made just for it. So I had to make a bracket to hold a hole saw and saw a piece of the case out to fit the new supply. Took over an hour.
I need to order a new supply. i see newegg has a huge selection. Any particular suggestions on which to order?
P.S. stuff is breaking faster than I can repair it. Still have an electrical circuit to repair. SWMBO just told me the wash machine leaks water on the floor. I just put a bettery back in the truck and the alternator won't charge. leaving everything to freeze for three months sure causes trouble. maybe i should just go back to FL.
Karl