I tried all that is mentioned in this thread and nothing works between my Note 2 (T Mobile S/W ver 4.3, Unrooted) and my Samsung KDL600B.
The very first time I had tried screen mirroring, it had worked like a charm, but then the next day it stopped working, and now I dont know if the problem is Note 2 or the Samsung TV.
Resetting option: Did the reset twice on my note2, once using backup and once as a fresh reset - both times it didnt work
Patch option: D/L ed the patch and applied it, still didnt work - now everytime i restart the phone, it says patch needed under patch but doesnt work after patching.
Mirroring from Video Screen: Even tried the option in the post directly above mine - that too didn't work (even with the developer mode enabled). Its a PITA - The note says its connected but the TV doesnt show mirroring, and then within a minute or so, the phone says "screen mirroring is now disconnected"
Fortunately I have a Chromecast, and with their latest update, the screen mirroring through chromecast seems to work, so thats a small saving grace.
Will stay tuned it to see if someone can resolve this issue......