My 63" buzzer recently got louder and louder, to the point where I couldn't concentrate on dialogue anymore. In addition the buzz came through my speakers via my Denon receiver; it got so bad I could no longer use the surround sound. I tried EVERYTHING, including power conditioners, special grounding, EMI shielding, acoustic foam on walls, etc. and a whole bunch of other stuff to no avail. 2 year old TV, and I'm about to drag it to the curb. Had a repair guy come out. He said Y board, but the boss said to replace entire panel (which comes with X and Y and daughter boards). $1200. He told me not to do it! Get a new TV, with warranty... or call Samsung and complain. So I called them, explained the situation and they agreed it was not acceptable. Gave me a 90 day warranty and agreed to pay for all repair work!! I was stunned!!! I didn't expect that at all. So the repair guy ordered the parts and came and swapped the panel last Saturday. Wow, what a job. Most of the guts of the TV are brand new now. The new boards looked nearly identical to the old ones, but I did find a few differences - a coil that is thicker and has a different number... stuff like that. The TV is now SILENT!!! Sure there's some normal plasma noises if you put your ear to the back, but nothing like it was. In fact it is much quieter than when it was brand new. And the picture is insane... I'm in love with my TV once again.
Sorry to update an old thread, but I thought this was important to share. My theory is these TVs don't have any active cooling, and may have received panels that draw more current than they were supposed to. So over time they cook themselves to death; the components loosen up, coils loosen, and it vibrate more than it should. Oh yah - my Denon is back to being silent... no buzz through speakers. I'm gonna assumed it was EMI leaking from the TV, and now there's none. Who knows, but life is good again. Samsung did a good thing for me. I won't hesitate to buy another one, especially since it seems they worked out the kinks on this model and didn't abandon it.