Monitor is blank

After restarting my computer, the monitor display the load windows screen then it just goes blank. The graphics card is a GeForce 8800 XP and the Monitor is a Dell 2008 FWP. If I turn off the monitor with the power button, and turn it back on the display shows my Windows desktop then goes blank again. The power light stays a solid green but if I disconnect the DVI cable it blinks amber. I have disconnected the power cable and tried to reset it but that was futile. I have a spare monitor but is uses the analog connection and the 8800 has 2 DVI ports. I even tried the other DVI port, that didn't work.

Could this be a Monitor problem or perhaps the graphics card?