I have an nvidia geforce 8400 gs video card , and i decided to upgrade it to an sapphire hd 7770 (Ghz OC edition). I know i connected everything right (including 6 pin connector) because when i power on the PC the video card gets power (Fan spins). The pc itself boots up nicely with no errors. but i get no display(no bios display or anything). I am posting this thread with my old card(nvidia geforce 8400 gs).
Facts: Video card reccomends 450 watt psu. MY PSU = 500 watts