Red Lines and No Attached Card

My extra PC boots up with redlines all over the screen.  The Nvidia driver program says there is no card attached.  I am running an EVGA Geforce 8800 GT that I got used has been working fine for quite awhile.  Its quite possible the card may have gotten really hot, I do not know.  Any input on what to do?

Any way you can post a Picture of what it looks like? I've had that happen just from a bad monitor cable before but it sounds more like the graphics card is failing. It is a bit of an older card, personally I would try putting fresh thermal compound on the card to make sure its not getting too hot. Other than that I'm not sure what to tell ya.