I purchased this 4K - 3D TV few years back.  Since last couple of months, for some reason it's developing PURPLE spots in many places on the screen.  Some spots are DARK PURPLE, some are whitish purple.  I see many are facing the similar problem with other Samsung TVs - but I don't see any solution provided.  What is the solution to this problem, I tried resetting the TV to factory seetings - it didn't resolve anything. ... View more