On Oct 24, 11:41*pm, David Nebenzahl wrote:
Dell-branded Sony Trinitron. Has been working wonderfully for many years
up until now. It's starting to turn itself off; the relay clicks, the
power light goes out and all goes dead. Turning it off for a few minutes
revives it,

The 'few minutes' of turnoff would be consistent with cooling
some temperature-sensitive component.

The 'many years' of work might mean that a blanket of dust
and cat hair has settled on the innards; it might be that all this
machine needs is a good vacuuming with the back cover
removed. Disturb not the anode wire unless you know
how to discharge it safely!