Computer shut down abrubtly mid-game.
Would not turn back on via power button when pressed.
Opened case, could see that motherboard was at least powered up passivley.
Attempted power on - posted then powered off abruptly within 3 secs.
Waited 10 mins - posted, got into Windows - then abruptly powered off again.
AM2 6000+, Ati4670. 60gb SSD, DVD drive .... 500w Antec PSU.Should have plenty of overhead there. Fine yesterday.
I think PSU as so much has to go right for Windows to work (even breifly).
Any chance it could be the motherboard?
To me, it almost sounds like your CPU is overheating. I assume your mobo isn't making loud beeping noises or you would have mentioned it, but not all mobos come with the little speaker that lets you hear it's cries for help. I'd check to make sure your cooler is fastened securely to your mobo, and maybe replace the thermal paste. To confirm this is the problem though, I'd let it sit for an hour or so, find a program to monitor CPU temperature, and watch what's going on.
I agree with Kufan, It does sound like it could possibly be a overheating problem, and you PSU is plenty big for what your running, so I do not think it would be your PSU. If it was your Mobo your PC would probably not boot up to windows, and like Kufan also mentioned you should be able to hear some beeps.
Although its kinda wierd how its overheating so quickly, unless these restarts you did where right after the shutdown during your (graphic intensive?) game. Leave it off for a bit before you start it back up again and also try to dust it out as well. Just get a can of compressed air and clean the case out. Dust clogging up vents and air flow can lead to some very bad overheating problems.
A couple programs that will measure your temps in your computer are Core Temp, and Speedfan. Just google them for download links.
Thanks for your help so far .... It seems temperature OF SOMETHING related for sure ... I started it up with case and i was able to play around the BiOS checking temps (CPU = 34 deg C / Case about 30 deg C) for about 7 mins.
Since i had the case off I assume this is nothing I can get around by adding a fan or two
Im off to pick up a PSU and cheap processor for trouble shooting. I fear it could be the MOBO Northbridge over heating - that would suck....
If as you say it is your northbridge that is causing the abrupt shutdowns then you need to check it and any other heat sinks on the mobo AND where needful renew their TIM with new stuff like AC5,sometimes the supplied TIM moves around and then you get a metal to metal contact,with attendant air spaces,,just went through a similar experience lately also..
You get better airflow with the side of the case on if you have a decent case so if you are overheating you can lower your temps with a few more fans because the side of the case off just lets in lots of air but doesnt flow that air across the right parts like extra fans would.