Shenan Stanley said:
If you go into your system bios, do you still see the hard disk drive and
the correct amount of memory? Processor speed still set as it should be?
It happened the same to me. It happened my Audio card, a Soundblaster, was
toast, and my USB VIA Card was playing havok with the rest (it was
exchanged for a NEC one). I removed both of them, changed with new pieces,
and now my PC boots again. It runs with no troubles since I repaired it,
one month and half ago.
When it malfunctioned, I couldn't even access to it in Fail-Safe Mode, and
the technician who installed me the new hardware said me that the first
culprit who oversaw were the memories.
So, I merely add to your sage advice that if the Bios doesn't give any
giveaways, you may try removing every PCI card, leaving only the AGP, then,
if boots, inserting them one af time. If even so doesn't help, ask your
technician to check the ram somehow (if you can't boot, you can't do it
yourself)