Har har! I've never seen a PC motherboard fry (except for those Athlon videos on TomsHardware), but I did have a pretty horrible experience with a Fuji C-41 film processor.
Where you load the film into the machine, there's a large cover that swings open, and there are wires along the door that let the machine know if the cover is open or not. Well, Fuji engineers decided to tape the wires right against the hinge. After a while ( a year or so after we bought it), the insulation on the wires wore away, and caused a short circuit. The wires on the door weren't carrying much voltage, as they were flimsy little wires like those that you see on CPU cooling fans, but they did cause the machine to stall. We then smelled something horrible, and realized the machine was in trouble. We unplugged it and called a technician to come in and fix it.
When he came in, he took off the cover of the machine and found the motherboard was fried. Literally. For some reason, he assumed the problem was a power regulator on the mobo itself, and just swapped the motherboard. Leaving the cover off, he turned it back on.
Things were going well for an hour, until he opened the door to load a leader card. As soon as he did, we heard a small pop (a fuse), and after a couple seconds, a HUGE arc of electricity about two feet high shot out of the motherboard, blinding everyone in the lab. I have no idea how much power was in that flash, but it blew a hole in the mobo, melted the surrounding plastic, and stank out the place for a few days. The technician later admit that it was the short in the loading cover wires that blew a fuse and shorted out the machine's power supply. They had to replace half the machine because of the burn damage. The poor technician was also standing right in front of the mobo when it happened. I have no idea how he survived, and managed to pull the plug.
Some of these machines are so badly engineered, they make MS-DOS look like UNIX.
