high pitched noise coming from computer

[Max]

I've tried unplugging everything and it seems that the noise is coming from
the motherboard, rather than any drives or fans. The noise changes slightly
when turning on/off the network. I disabled the onboard network and plugged
in a PCI network card, but the sound came back and is annoying as heck!

Any ideas what's going on?

-Max

 

[half_pint]

Dunno but it don't sound good. (no pun intended). :OP

Me thinks it will 'die' soon.

I think it may be coming from capacitors but thats a shot in the dark.

Try a google on "capacitor noise"

 

[kony]

I've tried unplugging everything and it seems that the noise is coming from
the motherboard, rather than any drives or fans. The noise changes slightly
when turning on/off the network. I disabled the onboard network and plugged
in a PCI network card, but the sound came back and is annoying as heck!

Any ideas what's going on?

-Max

What make and model motherboard?

See if the sound changes significantly when system changes from
near idle to full CPU load. That can be caused by running a CPU
stress test like Prime95's Torture Test,
http://www.mersenne.org/freesoft.htm

If that makes a significant difference it might be a choke.
I see that occasionally with chokes, last board I recall was a
Shuttle MN31N. They usually look like a doughnut with wire
wrapped around them, if you firmly put your finger against it the
sound should be greatly reduced or stop entirely.

My solution was to remove choke, "adjust" the windings a bit and
put some epoxy on it, then put back on the board. Putting epoxy
on it alone might've worked and could save having to
remove/resolder it. Note that epoxy ought to be one formulated
to tolerate heat, not hot-as-the-sun heat, but in excess of 80C
is a reasonable range, IIRC even some generic fix-it-all epoxies
like JBWeld far exceed 80C, but of course it should be
non-conductive, non-ferrous formulation.

 

[Mac Cool]

I've tried unplugging everything and it seems that the noise is
coming from the motherboard, rather than any drives or fans.

You are sure it's the computer and not the monitor? Sometimes it's
difficult to determine direction from high pitched noises.

 

[Matt]

What make and model motherboard?

See if the sound changes significantly when system changes from
near idle to full CPU load.

Wow kony, that is what I experience with my Biostar M7NCD Pro (nforce2)
with AMD Athlon XP 2500+ Barton. I've been wondering about that for a
year or so. The noise shuts off when the CPU is loaded and comes back
on when it is idle.

 

[Max]

Intel D845GBV motherboard. I always buy pure Intel for its stability, but
even Intel is starting to integrate more and more into their boards. The
noise correlates to network activity rather than CPU use. I've seen these
coils, I'll check it out. I might just have to upgrade my system early this
year.

(monitor is not even turned on, I remote into it)

-Max