Computer Not Booting

[offbrightness]

When I power on the computer I get past the first screen and when it gets to the next screen which is the ASUS screen, the computer powers down. After that occurs I power on the computer again and this time it doesn't turn on the monitor or even power on for more than 5 seconds. The latter continues to happen if I continue to try and turn on the computer. This is continually happening, any suggestions would be fantastic.

System Specs:
Motherboard - ASUS Nvidia P5ND2
Graphics Card - GeForce 8600GT Overclocked DDR3 512MB
HDD - Western Digital 320GB SATA / 16MB
RAM - 1GB T667UB1GV DDR2-667

Worth noting that the Fan in the case spins and the fan on the Graphics Card spins as well. Power On light on Motherboard is also lit.

Thanks again.

 

[James Mason]

what power supply do you have? and what CPU?
You computer specs look pretty old, it's possible your PSU is failing.

 

[offbrightness]

Power Supply - VIOTEK ATX Switching Supply Model VIO55 Watt 550 22A Where is the CPU located?

 

[James Mason]

Underneath your heatsink on the motherboard, in other words, kind of inaccessible to casual viewing.
Go to Start > right click on Computer > Properties > under System and Processor it will list it. (assuming you have windows 7, or vista, or xp, or 8)

 

[offbrightness]

Can't get the computer to power on or I would tell you what the CPU is. Um is it the Nvidia nForce4 SLI Intel Edition?

 

[James Mason]

That's your graphics card, you can't look at your CPU without taking off the heatsink and removing the thermal paste (which you HAVE to reapply with new thermal paste if you do remove, not that it's difficult or anything). You could try another a power supply, but you dont sound like you know much about how a computer works so I'm not sure if it's wise to be plugging things into the motherboard without experience.
Do you know anyone familiar with computers you can ask for help from?

 

[offbrightness]

I'm staring at the thermal paste, but yeah I don't have any handy to re-apply. I could try a different PSU.