computer wont start...

[nathan]

Hi everyone,

My computer went dead about 2 wks ago..(the com was on for a dew days) it turns on for about a second then turns itself of again, it keeps doing this, off, on, off, on etc.. untill i hold the power button to turn it off completly. i took the cd rom out, the harddrive and the floppy drive out. tried to see if the computer turns on without these, and no luck. so I took everything out of the case cleaned them and tested them all on another computer 1 by 1. the cpu first.. worked fine.. the pcu.. worked fine.. the powerlead.. works fine.. the rams.. worked fine.. the heatsink/fan.. worked fine.. could this be the motherboard being rubbish or can someone help please.. this is wat i have...

Pentinum 4 cpu, 1.80ghz.
pentinum 4 motherboard
40gb harddrive
256mb of ram
478 pin cooler

thanks nathan.......

[Tom]

Hi nathan. Welcome to ItsAllPC.

Did you try the PSU (Power supply unit) in another pc?

[nathan]

i have to coms, yes i tried the psu in the other come worked fine.. it now runs for about 5 mins but nothing on monitor, then goes off and sometimes it stays turned on but nothing on monitor ... :'(