It is not problem in panel! Probkem is in led s, i open my samsung ku6079 and when you look in leds some of tham are blue. That is a problem. I buy new set of leds and will replace it next week. Another problem you coud have is white rings, that is again probkem with led s. New set in Aliexpress cost around 20eur. You can change it easyly but you have to be carefull with panel.