The FIRST suspect for no picture would be the backlight. Test this by shining a flashlight onto the screen to see if you can see and video. If you can, then you have a backlight issue. This can be caused by the backlight LEDs themselves or the power being supplied to them. Now you must get inside to figure out what it is.
If you do not see any video, then it is potentially any one of the other boards. That elimination is more difficult. If you have a service manual, start with verifying the voltages from the PSU board. The follow troubleshouting steps to try to narrow the problem to a single board.