I could fix this problem with EEPROM reset. It works with and above UN7400 as I heard.
Press the physical ON/OFF button on your TV. Should be somewhere at the middle of the edge, mine is at the bottom side, behind the Samsung logo. So press the button an hold for at least 3 seconds. Then press the ON/OFF on the remote within 10 seconds and hold for at least 3 seconds.
You should see your TV rebooting 2 times. If don't, then try again.
Please note, it's a factory reset, so I would advise to save your channel list, picture settings, and so on first...