30" Cinema Display - pattern but no image

I have a two-year-old Mac Pro with 16GB RAM, an OEM Apple video card driving an aluminum enclosure 30" Cinema display. I just upgraded to Snow Leopard about two weeks ago and have the latest updated version. Over the past two weeks, when I occasionally leave the Mac unattended I would come back and the picture would be "jumbled" where I could still make out the windows and icons, but there was an abundance of color noise all around. Up until yesterday, a restart would correct the issue.

Last night I restarted after the picture did the same thing, only the screen diplayed a patterned gray background and never recovered. I could hear the drives cranking inside the box and it sounded like it was booting up properly. A couple of times (I tried to correct it by restarting several times) the pattern displayed and the screen went black - only the kind of black where you can tell the monitor is on.

To me, it sounds like my video card might have given up the ghost, but I wanted to the counsel of the gurus before I started making investments. Any help or insight is appreciated. Thanks in advance!