But a tech has seen such and it could be the panel or backlight. It's pretty hard to diagnose and if it's the panel, the cost to repair is too close to a new TV.
I had this model for more than 4 years.
But now everything I turn on the TV , I will get 3/4 of the horizontal screen dark and 1/4 at the bottom is normal. I have to wait for a while like 5 minutes and the top 3/4 dark will go away and the whole picture become normal display again.
I would like to know anyone facing the same problem and know how to fix this problem.