HELP Computer won't start anymore

[MacVista]

I have a friend who I helped build a computer with about a year ago. Over the last 2 months, the computer has just been shutting itself off randomly. I tried stressing different parts of the computer using various programs, and whenever the processor was at 100% cpu usage for a like a minute, the computer would shut off. Now whenever my friend tries to turn on his computer, all the fans start spinning, the hard drive works, but nothing appears on his monitor. What do you guys think is the problem? Should I have him buy a new cpu to replace the current? Or is it the motherboard/ram/video card? Is there any definitive way to tell? I don't think its the power supply since it was just replaced about 4 months ago. I don't have any spare socket 775 chips, ddr2 ram, or a PCI-E graphics card to test anything out.

Comp Specs:
Intel Pentium 4 630
Asus P5LD2
Corsair ValueRam 1gb 2x512 PC2-4200 in dual channel
Asus Radeon X700 128mb PCI-E
WD 80gb SATA hd
NEC ND-3520A 16x dvd burner

 

[Ricemarine]

More than likely the psu probably died.

 

[MacVista]

power supply again?... the computer actually starts though... like the fans, hard drive, and optical drive all work... just nothing comes up at all on the screen and the computer is totally unresponsive

 

[Ricemarine]

Originally posted by: MacVista
power supply again?... the computer actually starts though... like the fans, hard drive, and optical drive all work... just nothing comes up at all on the screen and the computer is totally unresponsive

Once again I suggest check the power supply, even though this situation is very common. Possibly get a 450w Forton for $50, or 400w for $40.

 

[Wall7486]

try booting with one stick of RAM.