Here are some tips and tricks for troubleshooting and fixing laptop video problems. Video issues are very common within portable computers and with the following tips you should be able to detect and eliminate basic laptop video problems.
LCD screen has a faint image or is very dark
Look closely at the laptops LCD screen, and see if you can see a very faint image. If you can then it is possible that the Laptop's LCD lid close switch is stuck in the closed position. In this mode the backlight stays off, even with the LCD lid open. This is to conserve power when the laptop is ON with the LID closed. Check the LCD lid close switch. It is a small plastic pin located close to the back LCD hinges. Try tapping the lid switch a few times to see if you can turn on the screen backlight. If that does not help, then I would suggest to replace the FL inverter board.