I've recently repaired the screen on my laptop.
It started its path to failure by randomly switching off the backlight, later developing to switching off the backlight if the screen was moved.
I could see a very faint image, but without the backlight to illuminate it there wasn't a hope of using my notebook without an external monitor.
After I pulled the notebook apart I saw that the problem could be either the inverter board (converting the battery DC to AC to power the flouro. backlight) or it was the backlight itself.
Cost of the inverter board: 15 quid incl. postage.
Cost of the integral backlight/TFT screen: nearly 500 quid.
So, bought the board as a quick & cheap way to either repair or diagnose the source of the problem, 30 minutes later replaced & reassembled and Lo! I could see again.
Bloody glad it was just the board and not the backlight!