Ensure the tray is empty
Press `Menu`
Press `9`
Press `Open/Close`
Press `5`
Region 1 - 6` should be displayed on screen
Enter Region code
Press `Mute`
If the above fails, try this combination
Close the drawer with no disc in it
Press Menu
Press 1
Press 6
Press 7
Enter region (1 - 6) or press MUTE for ALL regions
Press Exit