Enter, Enter, Up Arrow, Down Arrow, Enter
A screen will appear asking if you want to go into the Service Menu?
The screen will go away and just the regular picture will show. It looks as if nothing has happened.
But when you now press the Menu button, the Menu screen will have an S in the upper corner, indicating that you are in the Service menu.
To reenter the regular normal menu, repeat the Enter, Enter, Up, Down, Enter and follow the directions. The new Menu screen will no longer have the S in the upper corner.
Be sure to write down the original values before doing anything else!!!