It may likely be one of the boards, but without the ability to diagnose it, I can't say for sure if that's the case, and if so, which one it would be.
You can get parts by logging into samsungparts.com or by calling direct at 800-627-4368, and they would be able to assist with part orders (although they also would likely be unable to diagnose your unit based on the symptom).
I have a 42" Samsung HP-R4252. I've had it for about 4 1/2 years... Within the first six months I started getting pink/red pixels on the screen. Gradually it started spreading (more and more). While under warranty, the Samsung tech came out and said he needed to tune it. He said they never tuned it correctly at the factory (Mexico)... For the last four years I've had no other issues.
Yesterday, as soon as I turned on the TV, 80% of the screen had pink/red/white pixels all over it. Only a horizontal area (approx 4" wide) in the middle of the scree does not have this issue. I think it's the one of the circuit boards on the TV doing this (four years ago when the tech opened it I saw 4-5 circuit boards. Any thoughts how to proceed? Where to get the board(s)? How much it costs? Which circuit board it may be? And do I need to tune it? If so, how? Any information would be greatly appreciated!