I found an old 15 GB HDD lying around in a pile of spare computer parts. I decided to see if it would still work because it could be an emergency backup. So I plugged it into my ATX PSU only to find one of the chips on the board had several holes in it glowing red hot and it was smoking. A catastrophic failure! But why? What could cause the IC to fail so badly? The IC glowed for about 30 seconds before the supply tripped off. I have no idea on the circumstances of this failure - I did not do extensive tests, and I didn't examine the drive beforehand.
It was something like this, http://www.youtube.com/watch?v=ni_PA0as47g, but a different IC, and a different drive.