There were *tons* of Samsung TVs with this problem - plagued with a design defect and inferior parts in their power supply units. There are numerous DIY videos on youtube and how-to-fix-your-Samsung TV web sites showing you how to fix them simply by taking them apart and replacing a few defective caps.
I ended up fixing a 40" Samsung I had with this problem by replacing three 1000uF radial capacitors that had electrolytic leaking from them - rated at only 10V in a circuit that called for 12V-15V. Three new 25V rated parts from Radio Shack at $1.50 apiece, and it's been working good as new over the past couple years.
Granted, the fact that Samsung shipped SO MANY defective TVs with this problem is pathetic. But, at least it was easy to fix yourself if you had the inclination.
I ordered a manual on how to fix the TVand did order some capacitors and did replace them. Still didn’t work.