The ONLY time I've ever experienced this is when I received a bad graphics card. If possible check it in another system, but fairly sure you are going to need to RMA it. Just in case the card is good I want to make sure you are following normal procedures. Are you plugging in your monitor to the graphics card? or integrated? Are you using the same type of port? as in both VGA or both DVI? or have you been switching the interface? Hope we can help! God bless!