Monitor goes off randomly

[kirillka]

Hi

My specs are: MB GigaByte GA-965P-DS3 (rev 3.3); CPU - C2D 4300 overclocked 3.0GZ; 2 GB RAM@866; PSU - FSP GROUP 350W (PEAK 400); Video - GEFORCE 7900GS 256 MB; 1 HD and 1 DVD-ROM
Computer was working great for an year until yesterday. The monitor goes off (orange light only with no signal message) by itself after Win Vista starts (it can happen during Vista load or after 1, 5, 10, 25 minutes it loads), and computer is not responding. I tried different monitor and it still goes off.
I tried to play some music, and when it goes off, music continues to play, however the keyboard CAPS LOCK is not responding, and I have to press the power button to reboot. I also tried to set BIOS to defaults, the same thing happening. I updated the BIOS, updated Vista and updated to the latest Video Card drivers, still happening. Also I reseated the video card and wiped it with an alcohol, nothing helps.
So i wonder what can be the problem here?
Thanks.

 

[daveybrat]

1) try running your cpu at stock speeds only.

2) If still crashing after the cpu is at stock speeds, then the video card is most likely the culprit.

 

[robisbell]

PSU or Video Card is the problem.

 

[kirillka]

I tired to run the CPU at stock speeds, it was running for 15 hours, and today in the morning it crashed again (the monitor just went off, keyboard not responsive, only power button to reboot).
Can the CPU be the problem?

 

[robisbell]

More than likely it's the PSU.