Cmpaq730us problem

Recently I have purchased a Compaq Presario 730us. I removed Vista and hunted down drivers suitable for the components and all that good stuff. Everything is running on XP Pro fine. The problem relates to the laptop itself. There seems to be a strange buzzing sound.

I tend to have great hearing and none of my friends or family heard it until they got real close to the monitor and then heard the buzzing/crackling sound, albeit very faint. It seems to be situated near the back along the base of the monitor on the right side.

At first I thought it was the battery. Removal of that and using a plug didn't solve it.
Secondly I thought the monitor. After leaving it on and letting the monitor be auto offed, it still persisted.
So I thought maybe the speakers. I disabled the speakers and the modem and muted them and every other combination I could think of.

Anyone out there know what could be causing this? Incorrect drivers perhaps? (I'm using the conexant HD audio drivers and I installed the UAA.)

Or is it really the monitor? I'm confuzzled and I don't have much experience with laptops. Has anyone had this problem before?

Does your laptop have any sort of fan at the back of it? The fan could be loose or it could be hitting something in its rotation. Other than that I got nothin.