By small I mean a 20mm dia small white circles in a grid pattern are visble on the display, Its particularly bad on plain backrounds but evident all the time. Photos don't show it very well but I have attached one to try and help. You have to look carefully - its more obvious than this when watching. The TV model is UE50KU6000K and it just over two years old. We have four Samsung TV's in the house - I hope this isn't going to be a trend!
Samsung will refer you to whoever is their repair company for your area but the repair will be chargeable and in my case at least, uneconomic.
I did find a youtube video that took you through a repair but the guy doing it was a tv techy and had the right tools. It was a bit beyond what I was prepared to take on.
Agree that its pretty poor and the new tv that I bought from QVC to replace it had a sound fault so I returned it under their (QVC's) 30 day no quibble guarantee and bought a Sony from John lewis with a 5 year warranty built in.
I sold mine for a £100 to someone who wanted a games console.
50" curved UHD TV, some games console but the £100 helped.
I'have a look for that video but it was a few months ago now.