I have recently have had problems with my computer turning its self off!

it had been turning off but still being able to be used until one day it turned off and would not switch back on!

I thought it might have been my power supply, so i borrowed a friends old one. This enabled me to turn the pc on but I got no display on the monitor!

We tried taking all components out so we just had the graphics card and harddrive and floppy disc. This still would not boot. Now it gets weird, a day later i turned the computer on again and it booted up! then it crashed, now it wont boot - nothing gets displayed on the monitor

please can any one help me!

my system is

ECS K7s5A motherboard
Atholon XP 2000+ CPU
Geforce 4 Ti4200 graphics card by gainward
1gig of pc2100 DDR Ram

i am no expert by any means. have you checked the cpu cooling fan. if its not working then the cpu overheats and locks up. if you try and reboot all you get is a blank screen.
if however, you try and boot after some length of time, then the cpu has cooled and will work.
i speak from experience with this!