About 3 months ago my old GeForce 9600 locked up and burnt out after 2 years of faithful service, and I decided to go ahead and upgrade to a nice GTS 250 1 GB (XLR8 edition by PNY). At first this card worked beautifully, with an exception whenever I tried to play GTA4, but that game was not on my high priority list, and so I just played other games. About a month later, however, my entire computer locked up, and, being an impatient fool, I just hit the restart button and hoped for the best. What I got was a monitor that claimed it did not have an input, a hard drive monitor LED that would not blink, and a computer that could not boot far enough to hear windows noises through the speakers. Frustrated and broke, I decided to wait before I took it in to any shop to get it fixed. 3 weeks went by, and, still broke, I tried turning it on, just in case. Magically, as far as I can tell, it worked. Since this meant the problem was no longer a problem, I simply ignored the fact that my computer was out of commission for 3 weeks.
Now to the problem. This terrible crashing has occurred again. i just installed COD MW2, and due to the problems I was having with the game, I installed new drivers for all of my hardware. This, unfortunately, got rid of my nTune software and so my resolution was reset to 600x800. Since my display can run 1440x900, I wanted to change my resolution. I accidentally set the resolution too high for my monitor, and so the screen wouldn't recognize the input. I was going to change the resolution back in safe mode, but my wireless keyboard wouldn't let me press F8 before the computer had started up, and so I tried to reset the entire graphics card by turning the computer off and removing the card and replacing it in a different PCI express slot. When I turned the computer on, though, the entire problem had started again. I've tried both VGA slots on the card, combined with both PCIE slots on the motherboard, and althjough my computer turns on, nothing works unless I have the graphics card completely removed from the motherboard. I don't have an integrated graphics card, so I'm pretty much screwed. Anybody think they can help?
I had this strange problem too some time ago.
It did take a while to figure out what was wrong. Eventually i figured it out, it was a PSU fault.
This behavior indicates a failing or failed Power Supply.
Just replace the PSU and you are good to go . . .