I have a Samsung TV that I had bought for my mother as a Christmas Present in 2018. Randomly one day the TV developed a very dark line in the middle of the TV and Geek Squad at Best Buy told us that they wouldn't fix it and that Samsung wouldn't fix it neither. So I'm posting this here to see what can be done to remedy the issue because I don't have the money to buy a new 50' 4K TV just from a year and a half of use from the TV. Yes, you heard me correctly. This happened after only a year and a half. And the TV isn't even kept on all day. 50' NU6900B
@ajryte: I'm sorry to hear of your disappointment regarding this issue. Is the line present on all sources? Can you try unplugging the TV at the wall for around 30 seconds, then plug it back in to see if this helps? If not, go to Settings > Support > Self Diagnosis > Picture Test, and check to see if the line shows up in the test image, or if any 'Failed' messages appear in the summary. If the issue persists, then sadly this will need to be inspected by an engineer in your region, however if the device is over 12 months old then a charge will be applicable as it is now outside manufacturers warranty period.