I have an older model CM6730 (with no DVI port) and I installed an ASUS GT610-2GD3 graphics card to add a second monitor. When I plug the graphics card into the PCI-E x 16 slot on the motherboard, the video goes away on both displays. I have spent hours on the phone with ASUS and they absolutely refuse to provide any support. I can't believe that I am the only person on the planet who has encountered this problem. HELP!!