If any of you are doing electrical work that requires shutting off the main circuit breaker in your house, PLEASE PLEASE PLEASE REMEMBER TO UNPLUG YOUR COMPUTER AND ALL THE PERIPHERALS!!!
I got an object lesson in this item of prevention a few days ago. I was having the circuit breaker panel in the house rewired. Prior to the work getting started I shut all the computer hardware down and unplugged the television, sound system, etc. Since the computer is routed through a fully grounded surge suppressor, I figured that it was protected.
When the electrician reset the breaker for that circuit, there was a large bright blue arc from inside the tower. The diagnosis is a fried power supply. Thankfully, all the drives, CPU and RAM are undamaged. Now I just have to wait for Dell to ship a replacement power supply.
Scorched insulation has a very unique odor. It smells like $$$$.