I am having the same issue and it started 11/11 too. We've had ours about the same time too. Very frustrating!!
I own a 46" samsung lcd tv (LN-T461F) which just turned 20 months old. Til now, it was watched very infrequently (maybe 6 hrs per week). Last week, when powered on, it was functioning normally for about ten minutes before the picture went black, but continued with the program volume. Changing source/powering the set off and back on again did not rectify the issue, black screen with sound. I uplugged the television from the power outlet overnight, plugged it in and powered it on the next day, when it again functioned correctly for 25 minutes before it again reverted to black screen with sound.
I've done much reading of posts by 'gonefishing08' in the Samsung LCD TV LN-T5265F Black Screen Diagnosis Help thread, and have learned that faulty capacitors have proven to be he cause in many cases of other LCD Samsung televisions.
As the tv is out of warranty, Samsung was not willing to do anything nor would they admit to this being a known issue despite the multitude of people reporting/blogging about their same experiences.
I have taken the back panel of the television, but my ps board appears somewhat different in layout as compared to the photos others have posted of theirs. Mine appears to contain less capacitors which may only appear that way because of the differences in layout and the fact that there are three different capacitors there. While they do not show any signs of bulging nor leaking, I have removed 5 of them (from bourd locations CM853; CM852; CM876; CM8880; CB850). Two are samwha XC 10v 1000uf 105 degrees (caps blue with silver typing), one is samwha XC 25v 1000uf 105 drgrees (again blue with silver typing), and two more are sam young LXZ 10v 2200uf 105 degrees (black caps with silver typing). As stated earlier, none of them appear to be bulged nor leaking. I am confused as to why mine housed three different capacitors while most the other threads of people replacing capacitors on their boards seemed to have five capacitors all sharing the same coordinates.
My board model appears to be the bn4400-166b, in addition to the variations of the capacitors, the lack of discussions and pics matching my exact board/capacitor layout is making it difficult to decide what my next move is to be. Does anyone know if mine is meant to contain three different capacitors? And which ones I need to search for and would best replace them? Any help from someone with knowledge of this model and it specifics would be greatly appreciated!!