LG D-852 Smartphone: Screen problems and fix
This is an LG G3 smartphone with the back and bezel removed. The LG D-852 has some differences. Note the brown flexible flat cable at the top (yellow arrow). The LG D-852 has a rectangular and square one. Remove and reinstall both.
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.