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.