Strange PC behaviour...

[rajpoot]

The other day I was playing Fallout 3 when all of a sudden my system switched itself off.....not shutting down mind you....it was as if someone pulled the power cable from behind it, one moment I'm blasting away with guns, the next moment all I have is a blank black moniter in front of me.
I checked the power, the plugs, the points everything.
My CPU is certainly getting power, but somehow I cannot seem to switch it on....the on/off button in front does nothing, I even checked the wiring inside to see if the HDD is getting power or not, but I couldn't find anything wrong (though I have to admit I'm far from astute when it comes to the inside of the cabinate)...so far I've refrained from opening a little box inside the cabinate from where all the bunches of wires are coming out because it gives a high voltage caution, and well like I said I'm not very good at it....it just isn't switching on. I'm absolutly stumped.
Any suggestions would be most welcome.
Thank you.

[LeftEyeNine]

After reading the symptoms, I'd be sure to check GPU heat first, then would really be concerned aboutCPU overheating.

Does this happen when your PC is idle ? (e.g. when you're not playing games, encoding a video, anything which pushes your PC to its limits)

[rajpoot]

It has never happened before.....and if it's related to heating, it ought to start once cooled down, no? Unless there is some permanent damage? Oh boy....
Well, anyhow, it's been this way since two days now. Been using a PC at a cyber cafe since.

[Fragony]

Had the same, try a new graphic card worked for me.

[Marius Dynamite]

I had a similar but slightly different problem once. My computer kept switching off as though the power cable was being pulled out. Monitor, Printer, CPU. Every now and again it just went.

As it turned out what was happening was I was pushing the desk back onto the multi-socket adaptor which has a switch on it which cuts the power when flicked. I don't think that helps you though.

I dont know much about this stuff, but if your video card blew then I think your computer would use its very basic card and would still switch on in safety mode. Could it be the Power Supply? I had to get a new one when I got a new Video card because the power rating on my old one was too low.

http://en.wikipedia.org/wiki/Computer_power_supply

I think they are pretty cheap so it could be worth buying one and seeing if it works.

[Ramses II CP]

Okay, step one, pretty much every tower ever made has a light that comes on when you push the power button. Does yours still come on? What color is it now (And what color is it normally, green is typical)?

Oh, while we're still at stage one make sure it's not just the monitor. Will the monitor's onboard settings menu come up? When you boot the machine up does it beep, start the fans and HDs, and/or make the Windows startup noise? If you give it enough time to complete a normal boot cycle and then press the Windows key and 's' will it shut down?