Black Thick Vertical line on Center of LCD Screen...

I just had this same large black stripe going down my tv and I contacted Samsung, they had me do a power loop. Unplugged all devices, unplugged tv from surge protector for 60 seconds, then plugged tv into wall, plugged each device in one at a time to see if it came back. Then turned off tv again, and plugged back into surge protector. The black stripe is gone.

Black thick line down the middle and sides

the display of that region is broken u would need to get it replaced

Cleaned my tv, checked all connections. All seemed good. But it came back. So I gave it a small wack on top where the black stripe was. And voula