Well, the other day, I was trying to see how loud an old hard drive I had was so I hooked it up to an unused PSU, put a pin into the mobo connector to get it working, and it started up normally. Now, the PSU fan was almost as loud as the hard drive, so I decided to do something about it. Instead of doing the smart thing and opening up the PSU and disconnecting the fan, I decided to just turn off the PSU, stick a screwdriver through the vent to jam the fan, and turn it on. Don't know how I didn't foresee what was going to happen next. The screw driver didn't jam the fan as I'd hoped, but it jerked into another angle, then stopped, and trying to knock the screw driver out with a wad of paper towel I just caused the sparks to start up again. Finally I unplugged the PSU. The fun however, didn't stop there. The points on the screw driver which had shorted the PSU, linking what I would assume was a hot wire to the ground, melted on the screw driver. One of these contact points was the tip of the screw driver so that rendered it useless. Good times haha.