Lg 50ln5600 backlight issue

Sounds like the backlight has failed.

Do the flashlight test to see if the backlight is burned out, shine it behind the screen to see if and image is present.

If you can't see a faint picture with the flashlight then the T-con board is gone. If you can see a faint picture, then the led driver or ballasts for the back lights quit. You can get parts from here: TV Parts Universal TV Stands DLP Chips ShopJimmy

Back - light problem. Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis.
http://electronicshelponline.blogspot.com/
To some model sets; especially LED back-lighted types; the back-light inverter circuit will be part of the main power supply board [SMPS]. In such cases, the power supply board might need replacement. To some models sets, the back-light inverter and SMPS section circuit will be integrated at its main board itself. If so; the main board should be replaced. To some models of sets, all these section circuit will be integrated at its main board. If this is the case, you have to replace the main board.

Hello Dararius,
When you shine the flashlight at or near the screen and see the images, it means that the LEDS located behind the screen are not working. Since LED's don't usually blow out, it means that the LED driver circuitry located on a pc board inside the set is blown out and either needs to be repaired or just buy a new pc board from ebay such as the following:
http://www.ebay.com/itm/LG-EBT62679606-EAX64872104-1-0-Main-Board-for-50LN5600-UI-/361039485726?hash=item540fa15b1e:g:MBcAAOSwSdZWe5E0

It could be that the lamp is burned out on that side. Close up-, Shine a flashlight into it and if you see an image form it's simply the lamp. If not, then it could be a processor issue or something more complicated.

This is not easy to diagnose, either use a meter on the power cable to the led or check the leds one at a time

Testing TV Backlight LEDs - YouTube

? 4:44
https://www.youtube.com/watch?v=eEJoPCa7Kt0
Jan 24, 2015 - Uploaded by swappart.com
... explaining easy way to test individual LEDs on a strip from aTV backlight. ... Sharp LC-60LE820UN TV - LED Strip Testing - Long Version ...

IT02 - How to Test LED Backlight - YouTube

? 0:55
https://www.youtube.com/watch?v=YmSI2N6BGPA
May 20, 2011 - Uploaded by LCDPARTS
How to use IT02 to test Laptop screen LED backlight.

LST04-TV, How to test LED TV screen - YouTube

Hi Meleesa,
It is the backlight problem. Either the inverter has failed or the LEDs inside the panel have gone bad.

If the LCD panel back light is not lit you have a bad LCD panel. If the back light stays lit when the set is turned on then you almost certainly have a bad main board since you have already replaced the power supply and T-con.

I’m happy to help further over the phone at https://www.6ya.com/expert/dewayne_4a10eab6caecdb92