@thegibson - While soldering a PAL/NTSC switch onto my Amiga 500 I accidentally sneezed and soldered together several pins of the Agnus chip.
It took a few days, and antihistamines before I worked up the nerve to fix it.
Amazingly everything worked out, and I nolonger needed to use software to flip between PAL and NTSC modes, making it a lot easier to play games and demos from anywhere in the world. (at the time it was a big deal)
@thegibson - Addendum - I never again soldered on a motherboard. 😅