Clean Your Computer
One night I was sitting in the living room watching TV when I started smelling that all too familiar "burnt electrical" smell. It's the smell you get if you burn a circuit board and components. It's the smell you get if you bind an electric motor until it starts smoking. It's a horrible smell.
It took me several minutes to track down the smell in my bedroom to a power supply in a computer. A power supply that was red hot to the touch in a computer that was not even on. The power supply was simply plugged in. After the power supply cooled down, I popped it open only to find clumps of dust and a nice big burnt spot. No blown fuses. It appears that some of the dust caught fire right on the board.
Let this be a lesson that blowing out your computer every couple months is a worthwhile practice. I personally like to get my hands on an air compressor and have at it on the back porch. Don't use a vacuum. See the computer cleaning guide for more information on cleaning your computer.