I have a radeon 6570 1gb ddr3 video card, intel celeron e3200 2.4Ghz dual core cpu and 450w psu. Recetly i started having this weird problem, after 4-5 minutes of pc running, my monitor shuts down, then after 1 minute the pc shuts down, but the cpu fan continues working. I checked the temperatures and gpu is 30 degrees cpu is 35 one core and 41 the other. Also when i put the other video card everything works fine. What could be the problem?