I have the remote control from another Samsung TV and it works perfectly but the key combination to enter in the service menu do not work.
It seems that Samsung has changed things with newer models.
In German "Hifi-Forum" somebody said that you need a Smartphone App or a special Service Remote.
Maybe Googling helps.
Over one month after my first post and my tv is still vulnerable.
I have to disable bluetooth and due to this many functions like 3d aren't possible anymore.
Thats a very very bad job done by Samsung!