HDD buzzing noise

Hi,
I bought a new laptop, and I can hear an annoying soft, high-pitch buzzing noise coming from the computer, but only when the HDD light is OFF. So when it's light is on, the buzzing sound stops. I remember that this also happened on my old laptop's HDD, but I never figured out why. The buzzing itself doesn't seem like it's coming from the HDD though.
It sounds a lot like the buzz in transformers, but the frequency is higher.
Does anybody know what might be causing it?

 

If it's a Core 2 Duo then it might not be the HDD, but the CPU whining as it goes into a lower power state. This is a known issue for the Core 2 Duo and no one really has a fix for it, sadly.

 

does this buzzing noise start when you power the system up ?

If it is, it may be the fan which you are hearing.

If you think it is a transormer noise, put your ear to the power brick and listen to it, if it is making loud high pitchedd noises, you should probably get a new power brick.

K-TRON

 

Thanks for the suggestions. I think Hep! is right. I found a solution using RMClock here: http://forum.notebookreview.com/showthread.php?t=86494&page=2

I guess when the computer is accessing the HDD it jumps out of that power state so the buzzing goes away.

This isn't just a Core 2 Duo problem, it happened with my old Pentium M as well. I think it's unlikely that the CPU itself is making the noise since the noise seems to be coming from the center of the mobo (or is the mobo acting like a sounding board)? My guess is that when the CPU power state changes, the load on some switching power regulator is changed, something starts oscillating, and some ferrite-core inductor starts vibrating.

 

edit: Seems you found the same thing I was writing of. I'd still recommend reading at least the second paragraph herein.

It sounds as though it may be the Core 2 Duo CPU Whine (and you're right, it does occur on other processors - it just seems to be more of a problem with Core 2 than average). It only occurs when it is in the C4 sleep state - its lowest-power state - which it would probably not be in while it was processing data from the hard drive. To test if that is the case, follow the instructions in this post. If it causes the noise to go away, then it's the CPU whine.

The major caveat is that the RightMark CPU Clock Utility that can eliminate the whine also will cause your system to freeze after 20 minutes or so (it varies a lot from time to time) if you run it with C4 mode disabled while you are on battery. So don't use it unless you're connected to AC power. You can't do anything other than a hard reboot if it causes it to freeze. I've had to re-type a screen's worth of writing on a school desktop before because of my laptop freezing this way.

The other thing that inexplicably eliminated the whine on AC power, and greatly reduced it to the point it wasn't an issue anymore (from being a major issue) while on battery was switching from Vista to XP. I have no idea why XP would solve this problem, but it's something to consider.

 

Apollo13, does the whine only occur during UltraLFM?