It was a dark and stormy night when "Lou"
wrote:

Turn it off, then try to turn it on again, no dice. It won't come on. Unplug
it for a while, not sure how long - I've done a day, and it will fire back

Sounds like a thermal, and a can of freeze spray might do the
diagnostic. When you cold down the bad part, it'll start back up.

Without other data, this may take several steps, first chilling groups
of components. Then when you get lucky, chilling subsets, until you've
got it narrowed down.