Monitor powers up then goes black

I have two Dell computers. Dimension XPS-T and Dimension 4600.

Up until last week when I purchased a new FP monitor for the 4600 they shared a monitor via a KVM switch. There were no problems but now that I have removed the KVM switch and the XPS-T has it's own monitor (the one it was sold with) back, it has a problem.

The computer starts up and I see the Windows XP startup screen. The little green lights follow along under the XP Home logo and then it goes completely black.

I went into Setup and was able to set it "default" thinking this would bring back any settings on the monitor that may have been adjusted as a result of the KVM switch. Nothing has changed. It sits here with the power button flashing like it does when the CPU is off.

I know the monitor is connected correctly or I could not see the startup. It sits here as if in "Standby" but I cannot access Windows to check it out.

Any help would be greatly appreciated.

The new 4600 is humming along nicely with it's new Flat Panel monitor.