Hitachi ZAXIS 120-6 class Operator's Manual page 146

5. Push selector knob (2) to display Brightness Adjustment
screen (7).
6. Rotate selector knob (2) clockwise to make the screen
brighter, counterclockwise to make the screen darker.
f
NOTE:
 When the light is turned ON, the monitor screen changes
to night mode and mark (8) is displayed. Brightness can be
adjusted for day mode and night mode respectively.
 Even if the light is turned ON during daytime, you can
activate the daytime screen by pushing "0" (9) on the
numeric keypad.
OPERATOR'S STATION
1-64
2
MDCD-01-026
7
MDAA-01-172EN
8
MDAA-01-173EN
9
MDAA-01-018