I have a Samsung TV model code: QN75QN85DAFXZA that has recently started showing places on the screen similar to the attached image. The TV is barely one year old. Running screen diagnostics and unplugging for 30+ seconds does not resolve the issue. I cannot return it to Costco, where I purchased it, since they do not take returns on electronics past 90 days. What are my options? I am very disappointed.