I use an Nvidia 660 Superclocked on the DVI socket with a VGA adaptor because my monitor doesn't have DVI, I was messing around with the resolutions and then the screen suddenly when blue and said "NO VALID SIGNAL". I turned it off and then the system checked for disk consistency or something like that , It went onto the course of getting to the POST , and then when I'm about to go onto the desktop it just says "NO VALID SIGNAL". I tried to plug my HDMI cable into the card and then into the TV , it work's on that but I can't get the resolution down. When I used the DVI/VGA I used 1024x768 , my monitors native is 1680x1050 - but whenever I use that it doesn't even fit on the screen. I can't get this to work and I'm pretty annoyed , I looked for drivers for my graphics card but they are up to date , my monitor is listed as Generic PnP or Non PnP - It changes sometimes . The monitor is a Cello l2322af .
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Doesn't matter anymore - Turned it off and then took out the 660 and it works when i put it back in!