I have returned the TV and now have bought the exact same as sibren the UE43MU6179.
And I can confirm it works great on this model, so the UE40MU6120 does not work with this method!
On my UE65MU8000 I tried the same, but the LOCAL SET is not displaying.... Has anyobody got a clue what other key combinations might toggle this to become visible?
I confirm that this procedure works on tv ue50mu6102K.
I used a homemade cable with 2 ir leds from an old surveillance camera to send the ir codes and played the wav files with a laptop.
if you have a smart remote control , remember that once the TV has been reset, the remote control must be pared. I say this because after the reset the remote control turns on and off the TV (so it seems that the paring has not been reset) but all the other keys do not work and the remote control LED flashes.
you must make a paring as indicated in the remote control battery compartment and everything will work.