Strange video problem

[Azkar]

I helped my friend build a computer, and this problem is driving me insane.

He's got:

AMD Athlon 64 X2 4200+ Windsor 2.2GHz Socket AM2 89W Processor Model ADA4200CUBOX
MSI K9A Platinum AM2 AMD 580X CrossFire ATX AMD Motherboard
500W PSU
XFX PVT84GUDE3 GeForce 8600GTS 256MB 128-bit GDDR3 PCI Express x16 HDCP Ready SLI Supported Video Card
2GB Kingston DDR2
Windows XP SP2

Now, every time CS:S is run, about 2 minutes into gameplay the screen starts to get 'fuzzy' almost as if you are looking at a snowy TV, and the problem persists even after you exit to the desktop. If you remain in game, it eventually hard locks.

When playing UT2K4, it just hard locks after about 40 minutes.


Has anyone encountered anything like this before?

Any suggestions?

Thanks.

edit: I forgot to mention that it works fine when I put my XFX Geforce 6600 GTS in

 

[robisbell]

most common thing is the PSU is not powerful enough for the setup, when under load.
his setup will need probably a 550 or 600 watt psu.

 

[Azkar]

We'll try it when we get that card back, thanks a lot!

 

[robisbell]

why go back to a old card and not upgrade the PSU?

 

[Azkar]

I dont have an old (decent) card around anywhere that he could use

 

[robisbell]

the card he has now is fine, just get a better power supply. (PSU)