I am trying to upgrade my video card from an HD6450 and when I install it and turn the computer and monitor on, my monitor immediately goes into power save mode. I bought a new power supply (430w) and a new monitor and I get the same thing. Can anyone tell me what I am doing wrong? Or is there something I need to do in addition to just putting the card in? I have an HP Pavilion Elite 570t with an Intel Core i7 2600 CPU. The card I am trying to install is an AMD Radeon 8490. This is the fourth card I have tried. I get the same thing with all of them. Thanks.