I have an old medion laptop that has a DARK screen to it. I can see the desktop icons if I adjust the tilt of the screen when the light is on in the room. If the lights aren't on. I can see absolutely nothing. A flashlight held at an angle will also HELP to see images and text. The system is running windows xp and has nvidia graphics. When it boots up I have a bit of a time finding the pointer so that I can log on. The white box for my log in is easier to read than the login icon or name. This problem occured once before and simply corrected itself. On occasion one of my BOYS has put it down roughly on the car seat or thrown my briefcase onto it in the front seat and if it was glass it probably WOULD have cracked. HELP!It sounds like the inverter board in the lcd display has failed. You can buy replacement inverter boards for some lcds online and install it yourself, or you can take it to a repair shop and see if they could do it for you.I've experienced this problem twice before. The first was solved by pressing Fn-F8 or whichever buttons on your keyboard change the display mode (should have a picture of a computer screen or say something like "LCD/CRT"). As it turns out, my 1-year old nephew had been bashing the keys and had disabled the LCD portion of it by a stroke of bad luck.
The second was more closely related to your problem, with the display unreadable unless a flashlight is focused over it. The problem is likely the inverter, which can be easily and fairly cheaply ($50) replaced. However, as was the case for my old laptop, there's chance that the LCD bulb has burned out. Though bulbs are cheap, bulb replacement without damaging the screen is difficult at best and impossible at worst for many laptops. Unfortunately, the only way to troubleshoot is to invest in the inverter (system specific) and hope that it fixes the problem.

Good luck!