So, I was happily playing DiRT 2 when suddenly I heard a sound from the monitor and the screen just went dimmer. I didn't really care about it until i offed the monitor and turned it on again.
When I turned it on again, the screen came up and there was a hissing sound. After 1-2 seconds, hissing stops and the screen goes really dark. Shining a flashlight onto it at an angle, I could see images still. The monitor isn't blank, but just really dark. Turning it on and off again results in the same thing.
Sometimes, though, I turn it on and it works. I had the brightness set at 40. And this monitor is relatively new (8 months). Now, the monitor is working and I set the brightness to 15. Not sure if brightness affects it though.
This means that the illumination has failed, right?
Could be a power supply component in the screen -- the hissing could be a capacitor failing. If it's still under warranty don't try to fix it yourself but the link below may help you figure out a solution otherwise.