Chosen Solution
Model 60J6200 possibly back lighting problem. When a white or light screen there are shadow or darker areas. Does not show on darker screens. Almost looks like lights out behind screen.
@oldasmold it is possible that this is a backlight issue but I doubt that the backlight is totally out. It is possible that you have failed LED’s etc., but a completely off backlight would be far more noticeable than what you describe. Post some good images of what you see on your screen. Use this guide Adding images to an existing question for that. That way we can see what you see.
