Yup; I've had the resistors near the video out on an A1200 m/b in flames in front of me.
(Rewiring an Amiga -> SCART lead and got the 12V line shorting across the RGB lines)
Was most surprised and it was a reliable board until then. It still works, but I have to use RF with that one now.
I'm glad to hear someone else has had a good experience with a K7S5A - mine's great, although running @ 100MHz at the moment - not sure whether it's the RAM or the (not good) heatsink on the northbridge that's at fault.
I'll try again when I get some DDR RAM for it.
Oh, yes. I've also burnt myself on an IDE cable!
Was rearranging the IDE devices on a 4way adaptor for a different A1200, turned it back on and everything got hot. Definately damaged Gayle (or whichever runs IDE) on that one - it won't boot from IDE or if there's an accelerator attached.