No Power Except Power Light Blinks

[a5950]

Please help.
When I plug in the computer, the only thing that happens is the power light flashes.
Nothing else happens and turning it on/off doesn't change anything.
Needless to say the hard drive and fan don't come on.
Checked all plugs and can't find a problem.

The computer: SR1020NX Compaq Presario, Purchased in 2004
XP Home Operating System, 512 Ram

Any suggestions, please?

 

[OdiN]

Reseat your RAM and PCI devices. Reseat your CPU. Reseat the PSU Motherboard cable.

If it still does it let us know.

 

[Quiksilver]

^^^^^ make sure no cables came unplugged within the case.

 

[Sondra]

Could a bad power supply cause this?