(ok this was a few months ago now, but aint been on here in a while) Was modding an old pc for my mum's company and there was an old PSU which had a switcher between 240V AC and 160V AC. Was just putting the finishing touches to the computer, put it all back together, then it didn't turn on. Looked at the back and found it was switched to 160 by mistake, and without thinking of turning off the power i switched it: There was a flash of flame, the most outstanding CRACK you've ever heard in your life from the comptuer, profuse swearing and leaping about 2 foot into the air, from me. Needless to say i got the fright of my life, luckily no burns (my hand was right next to the flame), and i had to buy a new PSU, but nvm. Was tres amusing!