Low tech fix
Yesterday, an Aptiva that I bought for the kids started to make a rather ominous sound. Kinda like the sound a car with a low battery that won't start would make, but a bit slower.
My first suspicions were the hard drive. Hard drives are cheap, but re-installing Windows is no fun.
So with great trepidation I opened the case. I hadn't been in there a while, so I wasn't sure what I would find. I took inventory:
Two hard drives. One floppy. One CDROM. It didn't seem likely that it was the last two, so I figured it was one of the hard drives. That would mean a 50/50 chance it was the one that the OS was on.
At this point, I use a rather low tech diagnosis technique. I maneuvered to where I could place my ear next to the fully powered and operational hard drives.
The sound wasn't coming from there. Inches away was a fan over the CPU. That seemed to be the source.
I stuck my finger into the fan, stopping the motion. The sound stopped. I took my finger out. The sound resumed. I stuck my finger in one more time and looked around for anything amiss. I didn't see anything.
I took my finger out and turned off the machine. Unplugged it too, for safety. I then retrieved the vacuum cleaner. Positioned the hose right over the fan and turned it on. Did you know that those puppies make a rather high pitched sound when you get the RPMs high enough? Well, they do.
Once I was done, I plugged the machine back in and turned it on. The sound was gone.
It hasn't come back yet today.