I have a Dell D540 Studio desktop computer with a Nvidia 9800GT video card. A while back the machine started to display lines and characters across the screen that I thought was driver related. I upgraded and downgraded the video card drivers with temporary success until the problem seemed to reappear. I swapped to the other output port on the video card and finally moved the video connection to the vga connector on the motherboard of the machine with the same/similar results. I've run the diagnostics without any issue appearing. Can anyone offer an opinion as to what this is? Failed motherboard maybe? Something else? Any assistance would be appreciated prior to my call to Dell.