Windows 7 + gaming -> black screen

[pumparen]

Hi!

I have a big problem with which I hope you guys can help. I just built a new computer, yesterday to be exact, and it's all working fine except for one thing.
Sometimes when I launch certain graphich demanding applications I get a black screen. IN other words, it starts, goes into full screen and then boom, it stops. No sound, no nothing, just black. Only way to get out is manual reboot.

This is happening with among others, COD2. However, it is working flawlessly with WOW, although in window mode, havne't tried full screen for long.

GPU: HD 5770
MB: M4A79XTD EVO (have a CD which I haven't used with 790x chipset support)
OS: windows 7 x64 ultimate

I know PSU is sufficent, it's overkill. Also, it's not overheatnig because I don't even get a chance to start playing.

all help is appreciated!

 

[pumparen]

One more thing. When I installed the GPU, I installed with one 6 pin straight into the PSU. However, I also have one 6 pin cord which divides itself into two other cables that go to the PSU. Should I have used the other one?

 

[pumparen]

problem solved.

 

[steadfast1984]

problem solved.

in interested on how you solved the problem?

 

[pumparen]

Taking it back, I thought I did. I got the game starting once in a lower resolution, so I thought it was the monitor. But today I tried starting it again in 1024x768 and it didn't work. Also tried switching monitors, not working.

So, all help is still appreciated!

 

[pumparen]

also, it is not the game. Tried 3d benchmark, same deal.

 

[pumparen]

Solved it, got a new monitor and it turns out that was the problem after all