HP dv6552ea Battery Buzz ?

I bought this laptop 2 days ago and noticed than when on battery power is makes an electrical noise/whine/buzz ?

The noise comes from the botton left hand corner of the laptop, the palm rest and the center of the keyboard.

So yesterday I took it back in exchange for another, and to my dissbelife it also has the same problem.

The sound is not related to the hard drive or the cpu.

It' not theer in vista safe mode with or without networking, or on mains ac power.

It sounds like a compressed/mini version of a modem dialing or electricity surging throung circuits, almost like its struggeling to draw on power ?

Ive updated all drivers, bios, vista, unchecked usb hubs, disabled all non essential components in device manager, tried rmclock.......all with no sucsess.

This effectivly renders this laptop useless, as the noise is too anoying to make writing or quiet net surfing possible, so in reality this is a folding desk top !

What might be causing this ?

 

first, take out the battery
then, plug in the power cord
then start up the computer with no battery (just on power)
and see if the noise still occurs
if there is no noise, that means it is a battery problem

 

Obviously !

As I said, the things ok on mains power, but noisey on battery power.

 

I'm pretty sure that this is because CPU. Because Core 2 Duo processors have that buzzing noise when they downclock to save the power when they are on battery.

 

I have a 6500 and when I am on battery power I don't have any extra noise/buzzing. That type of noise that you are describing is a classic indication of a battery and or transformer problem. The only fix is replacement. Mabye you can barrow a friends battery to see if it still makes the noise. That way you would know that you just need to replace the battery and not the whole machine

 

Seems strange the same thing on 2 brand new laptops ?
(AMD 64, btw).

I can hear it, so can my mum, but my dad cant ? High pitch range ?