@ userlFIjAKWnzQ So sorry to hear this. Let's look into this further for you. Can you drop a private message here: https://bit.ly/2mQxylV with the full serial number, software version and if the symptom appears on all sources and the picture test?
I have a line across my Samsung tv. Model# UN65js9000 software version T-Hkpakuc-1530.1,BT-g/s. The line is a thin black line across the screen about 8 inches from the bottom. Thanks. Serial # is 03ud3cch100323k
Thank you for the information @Mike wolfe, if the problem returns could you do me a favor and run a picture test on the TV and let us know the results?