My samsung tv suddenly has dark section at the bottom of the screen. I found that many have the same issue.
For troubleshooting, I have unplugged all external displays from the tv, performed software updates, run picture test.
Then I called Samsung support, and they only adviced me to bring the tv to a tech, duh.
I'm quite disappointed with the customer service.
We can understand your disappointment, however, as the fault is evident on the picture test, this would indicate a faulty panel and would need to be inspected by an engineer. We've noticed that the TV isn't a UK model, could we ask where you are based?
I'm based in Australia.