email from dad:
For some time I had
noticed some noise when the computer powered up, but then
it would quiet down. I thought one of the fans must be
starting to have a bearing problem. Yesterday, there was
a noise that didn't quiet down. I opened up the case and
discovered the CPU cooler fan was making noise. Since the
power supply fan was also making the noise at start up, I
decided to replace both. I went to Fry's and found replacements,
although it was a little tricky finding one for the power
supply fan, since it only used two fat pins and the modern ones
use three small pins. The fans seem to be working fine now,
but after I have had the computer on for awhile, I start to get
a static-kind of noise from my speakers. I can keep working
by turning the volume down to zero, but the only way to fix
the problem is to power down the computer for awhile. The last
time it happened it sounded like the noise happened in the
right speaker before it started in the left. It appears that
something is heating up and causing the problem. Have you
ever heard of something like this before? It has happened to
me before, but it was very infrequent and didn't happen again
after you powered down. Now it seems like it eventually happens
every time I turn the computer on, although it may take a couple
of hours.
If you have any ideas as to what this could be, it'd be appreciated. I've never run into this problem. He does have an old sound card, though...