Sticky disc
In the early 90's we had a Compaq 33MHz 386 as a main build server, with a hard disc (can't remember the vendor or size) where they had made a bad choice of spindle lubricant. It would run indefinitely if left on, but if you turned it off overnight, the next day the disc wouldn't spin up when you turned it back on. The "trick" was to turn on the power, then lift up the whole case and give it a sharp twist. The inertia of the disc meant you overcame the static friction and the disc would then startup. Over time the twist required became larger/more sudden, but it lasted until we upgraded to a shiny new 486.