"Dave D" wrote:


You'll need to isolate the cause of the sound. Try stopping the CPU fan
briefly either by putting your finger on the centre hub of the fan or
unplugging it. Don't worry about overheating, an idle CPU will be OK for
several minutes without a fan before it gets uncomfortably warm. If the
noise is still there, go through all the other spinning devices one by one.
Disconnect hard drives and case fans and see if you can isolate the
offending item. Still no luck? Disconnect the cpu fan, case fans and all the
hard drives and power up. The only rotating item should be the power supply
fan. If the noise is still there, that's the problem.

I've seen quite a few noisy PSU fans, and the way they are mounted means
they can transfer a lot of noise and vibration to the case so it acts like a
resonating chamber. To confirm a noisy PSU fan, you can temporarily disable
it safely by powering off, inserting a plastic rod carefully into the blades
and powering back on. I've even stopped moving blades with a plastic
implement without any damage, but it's unnecessary for your purposes. Never
insert anything metallic or conductive. Don't run the PC for longer than
absolutely necessary with a disabled PSU fan, they get very hot rather
quickly!

Thanks, I'll schedule that for when I don't need the PC for a while!

But if this is a *beat*, presumably there are two components, not one?

It may be coincidence, but I've only become aware of this since
installing a third HD - a 200GB Maxtor Diamond, 7200 rpm, in addition
to my two 60GB Maxtors.

BTW, when it comes to disconnecting a HD to test its impact on the
noise, can I just close WinXP, remove the power plug from it and
reboot? On later reconnecting it, will WinXP have to go through any
hardware wizardry? My experience of that is mixed, so I like to avoid
it whenever possible!

--
Terry Pinnell
Hobbyist, West Sussex, UK