My LG D-852 suddenly developed screen problems, which included fading to black from the edges, then black horizontal lines, and finally just all black. It seemed odd that only today this would happen.
I found this post and decided to investigate. I took the phone apart, unplugged and reinstalled two connectors, which fixed the screen problems. It took 3 minutes, a very small screwdriver, and no additional cost.
The LG D-852 disassembly is pretty easy and repairable. Remove the back cover and then battery. There is a black bezel around the back, but is actually in two parts. You are looking for bezel part at the bottom of the phone. For the top bezel all you need to do is remove the screws close to the bottom bezel, to allow the bottom bezel to slip out.
Look for two ribbon connectors, called flexible flat cables, both close together on the board. One is rectangular and one is square. Using a small flathead screwdriver pop them off the board and then reinsert them back onto the board.
Button up the screws, reinsert your battery and power back up. This fixed my display issues.
Overall this LG is easily repairable. I do like that there was no glue used, that screws were easy to remove and reinstall. Yay for LG’s design team.
2019 Mar 29 This did not fix the problem. I have tried this hair dryer fix, How to fix LG G3 no Screen and Screen Fading Issue | Permanent Fix, second video, so we will see if it works. It was not difficult nor did it take long. The screen did come back as it should.