I figured I should follow up on this sad little story, as it might help someone else out there, someday....
I did eventually pull the unit apart and turned my immense mechanical/electrical knowledge (COUGH, CHOKE) to the guts of it. I eventually worked out that there is an electrical switch that is actuated by what I will call a thin plastic sensor prod that passes into the flow tube inside the unit, where the hose hooks up.
If you attempt to run the unit without water flow, which I did, this prod pushes up and flips the switch as a safety cutoff for the pump. On mine, it stuck in that position, preventing the pump from running.
I simply pushed it back in place and the unit now functions fine.
Something to remember if your teenager, SO, etc., reports that your pressure washer has suddenly crapped out "for no reason".
Cheers to all