All this talk of computer gremlins suddenly reminded me so something. I once had a laptop that would never the battery out of box. I first I thought it was the battery and ordered a replacement under warranty, but no joy, it only worked without being plug in until the new battery died. It was my first laptop so being used to "wired" computers and not wanting to dick around with it anymore or spend more money on a new computer, I just used it with the cord.
Anyway, in the later years of its decade or so life it started misbehaving, and my usual remedy was to simply unplug it, which
always resulted in an instant blank screen. Until one day, when it again froze on me (or simply pissed me off, I can't remember
), I pulled the plug, and it stayed on for like 10-15 seconds
(cue The Twilight Zone theme). Never did that before or after.