Monitor stuck in Power Save Mode

My Dell XPS has a 3.2 ghz CPU,maxed out on RAM (4gb)and has a Nvidia GeForce 6800 PCI-Express x 16 256mb (DVI/VGA/TV out)graphics card installed. I left my computer on overnight and the next morning the monitor indicated that it was in the "Power Save Mode". The monitor power button had a steady amber light and after moving the mouse and pressing several keys, it remained in that mode. I checked the cables, removed and reinstalled the graphics card to no avail. The fan on the card still functions,the computer's power button is steady green, and the diagnostic lights indicate a possible video card failure (2-4). My question, do I need a new card and if so, what would be a good compatible upgrade for this unit? Nothing fancy,just something similar.