My legendary ill luck with computers has continued today.
I got a KVM switchy-thingy so I could just the same keyboard/monitor/mouse with both my main linux box and the Windows box I occasionally use for games (or stuff that just must be done in something MS).
Unfortunately the cables or the switch itself isn't that good quality as the video signal was being reflected (everything had these lovely ghost echoes that hurt my head).
So.... decided to return that, and just test the screen with my windows box, which had been recently moved to the main desk, but hadn't been used for a couple of months. It decided not to turn on. Not even just to twitch the fan. Grrrr. Probably a power supply...
I am taking this to be a hint that I really should not be playing games while I house-sit.