HD 6850 video card issues

Hi,
So in a nutshell I put my system together and got a lightish blue screen with strips running down. I should also throw in that it works for 5 minutes and then it randomly freezes.

I'm pretty sure the two things that could be wrong is my card and the psu.

psu=Corsair CX600
card=Sapphire HD 6850

I've tested everything else and it works fine, I just don't have an extra psu laying around. Put in a old GeForce and it worked, used drivers that were included, downloaded from ATI and ones that windows 7 found all with the same result.

What do you guys think the problem is? I know my psu isn't great but the watts and amps seem to be enough(unless corsair really overrates it....)

I'm sure it's not your PSU. What are the temps of your graphics card?

Well fan might not be running on the GPU. OR, they could have screwed up the install on the GPU's heat sink....

BUT, no matter, if you've done all you can with drivers... then I'd say it's a DOA on the GPU card and RMA time.......

On the Corsair, there's a ton of power there for a single card. And if its new, power supplies either work or they don't (there's no low or limited power situation with a new supply....). If it works with the old GeForce then you have a known good supply...