I recently acquired a free 17 inch monitor in addition to another monitor I have, so I can use my 2 computers now. Problem is the monitor is a bit screwed up. Even though the brightness and contrast is maxed at 255 it remains quite dark and hard to see, now this monitor did work at one time, and if the contrast and brightness were at a medium value I know that it would work right. The problem is that it needs to be 'reset' or something along those lines, theres not a button like most monitors, its a switch in the back, but when u tune it off then on the settings just reverts to the same color. Is there such a thing as an internal reset button?
I can't find what model it is, but it seams like if the settings were normal it would work, but I suppose it could be burned out, I don't think its that old, not more than 5 years I think, I will find the exact number though later.
What type of video card are you using? My Sapphire 9800 Pro had dark output through the DVI with a couple old Catalyst drivers. Try switching your two monitors so you can see if it's a bad monitor or card. If it's the card, update drivers.
I have seen a few monitors with the problem you are describing - both times i can remember it was terminal.....monitor was on the way out. However one of the monitors still works to this day in its "half burned out" stage.