i am new to this forum but have read a few articles here and i liked it
so i decided to post my problem which i have been facing for some months now
well i used to have reboot loops
after replacing two graphics and a host of other things
i finally found the culprit was overheating.
The fan on my psu was not working and thermal paste on cpu heatsink was not good.
Fixed both of them.
Replaced my damaged video card.
Check my ram
and finally got the pc up and running.
So i finally had it done and dusted .
But i was wrong.
Last day , when i switched on power supply , then the ups and finally the psu.
The motherboard got on and i pressed power button , it started smootly into windows.
then i started playing fifa 11 for more than half an hour and suddenly the turns black.no video outpost.i looked at the motherboard and found out that the led was also off.
Everything off suddenly.
note : the psu was still on but the motherboard led was off.
So i switched the psu and switched it on again
the led turns green and again it booted fine.
Again an hour or so , same thing happens , no video output but the computer was on
the led was on and the power button on my front was blinking green.
So i thought it might have gone to sleep .
So i restarted and again it booted fine.
Untill when the windows logo came and it goes off again , this time the mobo was off altogether.
I thought it maybe something serious so switvhed it off and i am trying to figure the problem.
Seems me and you are having a similar problem, but yours is a bit different than mine. My motherboard light is still on, but I can no longer power on my PC. It just shut off randomly again and now it won't power on. All I hear is the PSU, GPU, and case fans powering up and then shutting back down. I've already replaced my PSU, applied new thermal paste, and added more fans for cooling, nothing helped. Seems like it's a motherboard problem for me... bummer. Hopefully, yours is a PSU problem, which is what it sounds like.