Troubleshooting a friend's PC

[Protomorph]

A friend of mine asked me to look at her PC, telling me it would not power on. It started when she tried to update her CD-ROM drivers, after attempting to install cable internet programs and the compy saying it could not find the drive. She has not had the thing very long (bought it from a friend) but was working.

I took the disk out of the drive using a safety pin and hooked it up. I noticed the cdrom drive had been unplugged. Hit the power button, and her windows98 loaded as normal. I powered it down and plugged the CD drive in. Upon hitting the power, it did not boot. The only thing that happened was the power supply fan started, and the speakers crackled briefly.

I unplugged the drive again, and got the same result, nothing. Unplugged the hard drive, still nothing.

My first instinct is the motherboard, but I thought I'd run it by you guys and see what your opinion is. Perhaps someone has run into this before.

If it matters, the compy is a HP Pavillion desktop 8560C

[Panther_Gunn]

So, the CD ROM drive was *already* unplugged?  Did it *ever* work for her?

The fact that it still won't boot up again after it's been taken back off is odd.  The only thing I can think of to add would be to check in the BIOS for the boot sequence.  Perhaps taking it out of the sequence completely (or at least, putting it after C: ), would make a difference. 

I've seen plenty of strange symptoms in my day, and plenty of strange fixes that *shouldn't* have had as much to do with the problem, but still work anyway.  Like having to unplug *both* ends of the power cable to a PC for a few minutes before it would boot again after locking up.  :wacko:

[Protomorph]

Oddly enough, the thing will power back on...occasionally. every hour or so, it will work. Now, I'm wondering if it is the power supply. It's like the cpu isn't getting the juice to kick on, or something.

I plugged the drive back in and booted it, and the system locked up on startup. I unplug it again, it's ok (except for the whole...power thing).

I put another cd drive on it, and when it boots up, it does not lock up the system. It is still doing the same thing, though. Only boots up some of the time. You hear it try to, but the thing just can't get up and running.

[Panther_Gunn]

That *could* be a p/s problem.  When it doesn't boot, do you get any kind of POST beeps?  Are you able to get to the BIOS?  At this point I'd recommend swapping in a different p/s to test.  Did HP go with a crappy proprietary hardware system the way Compaq did?