When I put in my XFX Radeon 5450 my Dell Optiplex won't show anything on screen. Only when I remove it will it work. It wont work even if I take out the vga cable and put it in the integrated video, only when the gpu isnt in. I tried putting it in and takng it out and back in but nothing. The cpu fan spins slowly whilst this is happening. Any ideas will be greatly appreciated!