Tradesman1 :
Sounds like the panel is going, should be under warranty, would call Samsung
Thank you, I was planning to do so and now it is confirmed.
May I ask, is this something that happens often? This is the second TV I have tried in a matter of two months (the first being a Vizio of a similar description), and the picture is incredible (when it is working), but I don't want to get another one of the same type, if this commonly happens.
Thank you for your help!