GPP Series User Manual 
92 
Backlight 
brightness 
adjustment 
In the System menu, press the F3 (Setting) 
button followed by selecting the F2 (Backlight) 
to adjust backlight brightness. There are three 
brightness levels: High, Middle, and Low. Select 
from pressing the F1 (Low) or F2 (Middle) or F3 
(High) button. 
In the System menu, press the F3 (Setting) 
button followed by selecting the F3 (Beeper) to 
turn on or turn off the buzzer beeper. 
In the System menu, press the F3 (Setting) 
button followed by selecting the F4 (Upgrade) 
button to upgrade the machine to the latest 
software version. For more details, refer to page 
93. 
In the System menu, press the F3 (Setting) 
button followed by selecting F5 (Hardcopy) to 
proceed to screenshot operation. For more 
details, refer to page 94. 
Restore to 
Factory Settings 
In the System menu, press the F5 (Preset) button 
to restore to the factory default setting. For more 
details, refer to page 88.