Set LCD Contrast Level
Select "F2: Set Contrast Level".
The display can be made lighter or darker to suit the background lighting. The desired contrast can be achieved by pressing the "SHIFT" key, causing the green lamp to light up. The display can then be set to the desired lighter or darker level by pressing "Arrow up" or "Arrow down".
NOTE: When the desired contrast level has been set, the "Shift" function must be deactivated by pressing the "Shift" key again so that the lamp above it goes out. If this is not done the "SHIFT' function will continue to lock the keypad.