The semi-ancient electrophoresis power goes on the fritz, so of course we open it up to see what's what. Lot's of discrete logic, some massive (1 milli Farad each!) capacitors, a couple of Motorola 68000s. Nothing obviously amiss, and no hope of figuring out what has gone wrong.
But we did get this gem: "Oh, that's where the beeping noise comes from." That's what makes it all worthwhile.