Whew, crisis averted.
The computer we use for running our scanner does only that. It runs the scanner and it does that just fine. That computer is a Dell 8400 just like the one I am using to type this. It is a 10 year old machine. The battery backup that keeps it happy with electricity started beeping that the battery had to be replaced. OK, shut down the computer, replace the battery and hit the power button and zippo nothing nada silence. Uh oh.

Fortunately we have 4 of those exact same Dell 8400 10 year old computers around here. Once before we thought we had a power supply issue on the machine we use for the fax and copier and we bought a power supply. That turned out to be a different issue so we had a spare power supply on the shelf. Swap in that power supply and the magic smoke stayed inside the wires and the computer booted up just fine. Fixed for no cost.
Now I need a nap, that was exhausting!