I have the exact same problem with the same model. The backlight of mine is done. Try the following: Switch it on and make sure it shows the image for a second. After it went dark, shine on the screen with a strong flashlight and check if you can make out any part of your desktop. If yes, the image is still there, but the backlight is broken. Mine broke four months after warranty and now I'm faced with a costly repair - or replacement. Both suck substantially...