Hello,
I have good news !
I managed to reach Samsung support, they told me that it was not possible to rollback to S-Player with the panel.
A factory reset was necessary.
For those who wonder how to proceed, for a QB50B screen, you have to follow the following steps :
- Turn the screen off with the remote control
- Press Mute>1>8>2>Power on (one by one, this need to be done within 2 sec)
- In the upper-left menu choose Option>Factory reset
- Delete screen from the installation
- Turn the screen back on
- Reconnect the screen to the MagicINFO installation
There we go ! Now we can put back on Lite or S-Player mode.
Regards,