I have the LNT4661fxaa. Started having problems very shortly after warranty expired. After much frustration, 2 trips to the TV repair shop, and around $1,000 later I noticed 3 blown capacitors. Replaced them myself...same problem. Then I see on this site someone mentioning humidity. I started noticing that it only stopped woking when it rained. EVERY TIME. Now I just get my wife's blow-dryer and force hot air in the back and 1-2 minutes later it works. EVERY TIME.
I know this doesn't solve any problems, but can help. I wanted to throw my TV out the window before. Now its just a little annoying.