How can I fix the rattling noise in my computer?

Episode 1088

Patrick from Burlington, MA

Patrick's computer fell off the desk onto the floor. Now it makes a loud sound when he boots it up. Leo says to turn it off right away. He should make sure he eliminates static electricity and then open it up the case and inspect the fans. Chances are, one of those fans was dislodged and it's getting in the way of the fan blade of the computer. That could short circuit the PC.

How can I prevent my subwoofer from humming?

Episode 1041

John from Ottawa, IL

John just bought a powered subwoofer for his home theater and when he plugs it in, it makes a humming noise. Leo says that's called a "ground loop" and there's ways to fix that. The plug isn't properly grounded, or could be loose. Or the stereo itself is causing it. John should go to RadioShack and get a magnetic ferrite coil that snaps onto the wire. That will eliminate it. If it doesn't, then an electrician may need to check his wiring and power.