i just got a geforce 7900 GS. switched out my old PSU because it didnt have enough wattage or current. New PSU has 600W 12V 20A. When i turn on the PC everything runs just fine. Heres where the problem starts. When i try to run a low end game say like counter-strike 1.6 or starcraft it runs fine, picture and everything. When i try to run a more high end game such as Counter-strike source or HL2 my screen goes blank but i can still hear the background music. Currently im using the drivers that came with the GPU but im going to update with the lastest from the Nvidia site in the next few days. Any ideas on what might be causing the video problem?