Same issue just started appearing intermittently on my UN55JS7000 TV as well. It eventually became permanent. After much research I found someone who replaced the LED backlights and claimed they fixed the problem. Since the TV was out of warranty, and I didn’t want to pay a repair man hundreds of dollars to diagnose and fix it. I decided to take on the repair myself. I ordering replacement Backlight LED strips (Samsung BN96-38481A/BN96-38482A LED Backlight Strips), and 2 suction cups to remove the panel from ShopJimmy.com. There are many disturbers of replacement LED strips. Just search the product number above to find the closest and cheapest ones in your area. I paid $90 CAD.
I also found this video https://youtu.be/-hLjDjKKvM0 on YouTube showing how to perform the repair. It wasn’t the exact same model, the the disassembly was identical to our TV’s. The video isn’t perfect but it does show how the LED strips are replaced, and as well some mistakes not to make yourself. The hardest part was finding out how the few frames were clipped, and how they held the thing together. With patience and a butter knife I finally figured it out. I was able to make a full repair by just following the video, and fixed it myself. I saved myself a lot of money in the process. Hope this helps.
