I decided to bring my office PC into the XXI century by adding a few USB ports to it.
I turned it off. I plugged in the board. I started screwing it... and dropped the screw inside it.
That has happened a billion times before, so I'm not too worried... until suddenly the computer turns itself on, and a awful smell comes from the ISA end of the mobo, along with acrid, black smoke.
I pull the plug, and it doesn't work. It seems to boot, but it makes a constant beeping sound.
I put another keyboard.
It all works, except the power LED is now always on as soon as I plug it. But the computer isn't. When I press the power switch, the power LED gets brighter, then it starts.
I wonder what exactly I burned :-)