Major Broken PC Help

[Pally321]

Hey guys, I've got this PC I'm sick and tired of by now because I can't get it to work, here's the deal:
It's been sitting around for a while and I want to fix it. It turns on just fine, it sounds to me like everything's turning on, but there's absolutely no response from the screen. I know it's not the VGA cable because it works fine on everything else. Some thing I've tried are: Reseting the CMOS, reseating the hard drive, and reseating the RAM sticks individually. I'd rather not spend the money on a hard drive or power unit just to find out that's not the problem. So any ideas?
And here's a full spec sheet for the computer: http://h20000.www2.hp.com/bizsupport/Te ... gR1002USEN

 

[Mako321]

What does it do when you have nothing plugged into it but the CPU?

 

[Pally321]

What does it do when you have nothing plugged into it but the CPU?

You mean with the PSU still plugged into it, right?

 

[Mako321]

What does it do when you have nothing plugged into it but the CPU?

You mean with the PSU still plugged into it, right?

yeathat

 

[Pally321]

What does it do when you have nothing plugged into it but the CPU?

You mean with the PSU still plugged into it, right?

yeathat

Notsureifsarcasmor...

 

[vskid3]

Unplug the PSU and try to turn it on.

Its assumed that the PSU is plugged into everything it needs to be plugged into.