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.