I have a Lenovo Thinkpad Edge E520 that emits a high pitched whine from the top lefthand area of the keyboard when a 2.4ghz wireless USB mouse is inserted. The sound is a lot louder while on battery power. The noise goes away after removing the mouse, and inserting it causes it to start back up again.
Disabling "CPU Power Management" in the BIOS solves the problem so I assume it is related to CPU sleep states as I've read around the internet. I don't want to leave this disabled as it decreases battery life.
I posted on the Lenovo forums and they were not much help. I had the exact same model that exhibited this behavior and I exchanged it for a new one which has the problem as well. Anybobdy have any ideas?
edit: The sound lasts as long as the mouse is inserted and the cpu is relatively idle. Also, the noise occurs with multiple 2.4ghz wireless mice I have... bluetooth mouse does not cause issue.