Samsung UN55MU850DF - One Connect

4-2-3. One Connect
TV Power’s On with no on screen video or Menu 
Power the TV "1. Off".
Unplug One Connect Cable to the TV.2.
Power the TV "3. ON"
[One Connect disconnect banner will appear.]
If there is a problem in the One Connect and the TV Panel is OK the disconnect banner will appear.4.
Replace defective One Connect Board.5.
4-10
4. Troubleshooting