This might seem counter intuitive but hook up an hdmi cable to your computer and create a picture (must be fullscreen) of white. And only white. Let this sit on the screen for an hour or so, then power it off for an hour or so, then see how it is. Repeat as necessary. White makes all colours of the pixel activate and essentially resets any burnt pixels. I had this happen to my Tv due to bad burn in from the mine craft HUD, and it solved it after a couple hours. Good luck