My NEC Multiscan 70 (avoidatallcost COUGH) is making clicking noises (and the powerling blinks each time) when the computer is turned on. Nothing appears on the screen.
I have the same clicking going on with my MultiSync XP17, it occurs during resolution changes.
When you say nothing on screen do you mean the monitor dies on you or just goes black for a second. If it's the latter I believe it's normal for NEC displays. If not your monitor may be dying.
Syngod said it all. Also, I have what I believe to be the exact same monitor for 2 of my machines. One machine has the Iwill XP333-R on it and the video happens to come up slower on that system than my other machines. The monitor will click off for a few seconds, but come back on when the system starts to boot.