I have an old P4 PC I bought second hand (for £45/$60!) but it appears to be on its last legs. I occasionally have to hard reset it when it freezes (usually playing flash video), and this causes it to "forget" the DVI connection and revert to VGA. As it's connected to a TV that has DVI but not VGA, I then have to connect the monitor from my other PC to the VGA port, clear the BIOS, and reboot. The PC then boots into Windows fine and I can set up the DVI port again.

However, I had to do a hard reset last week and now the above steps don't work. When I boot up, I don't get any beeps, so the I assume the BIOS is fine (or completely dead!), the CD drive spins up, but I can't hear anything from the hard drive (and the activity LED doesn't flash like I think it used to). The whole time, there's nothing output on the VGA port. (The PC has an AGP graphics card with DVI and VGA ports, as well as an integrated graphics chip - I don't get a signal on either VGA port. I tried rremoving the graphics card and I still didn't get a signal from the integrated chip.)

The main specs are as follows:

MSI 865GM3-LS motherboard
Pentium 4 2.8 GHz
512MB (originally 256MB, I upgraded a few months ago)
ATI 7200LE AGP graphics card (low profile)
Integrated Intel Extreme 2 graphics

Any advice would be greatly appreciated.