User's Manual

18 Revision 2 GM550 v1043 FCC-IC.doc
Contrast
Adjust the LCD contrast to optimize visibility.
Step 1. Press Menu → Next → Next → Enter → Next → Next → Next to go to menu 3D) LCD
contrast adjustment.
Step 2. Use Up and Down to adjust the display contrast.
Step 3. Press Next to advance to the backlight adjustment page or press Exit twice to return to
the operation display.
Backlight Mode
Adjust the LCD backlight control mode to conform to viewing and power supply conditions.
Step 1. Press Menu → Next → Next → Enter → Next → Next → Next → Next to go to menu
3E) Backlight mode.
Step 2. Use Up and Down to select the backlight control mode. The LCD backlight can be
always on, always off or on a four second timer. In the four second timer mode the
backlight will come on for four seconds when any button is pressed.
Step 3. Press Next to advance to the backlight adjustment page or press Exit twice to return to
the operation display.