Alignment and Adjustmens
Samsung Electronics Service Manual
6-3
- Firmware downloads mode function
Turn on the printer at the same time that the button is pressed.
If all LEDs scroll, release the button and download the firmware ROM file via USB port
Black only key input process
: After the panel task is received the Black only key detection event, it changes printer mode to Black only
mode and notifies driver that the printer mode is changed to Black only mode. If printer mode is Black
only mode, driver makes printer image by only mono excepting color and the Black only LED glows.

6.2.2 LED Function

There are six LEDs present. Status led indicate the error/online status of the printer in idle mode. In error
mode, the status LED glows by red color and in ready mode, it glows by green color. The other four LEDs
indicate the toner status. If the black toner needs to change, the toner-low (black) LED glows and if the
color (yellow, magenta, cyan) toners need to change, the toner-low (yellow, magenta, cyan) LED glows.
Black only LED indicate the printer mode. If the users press the Black only button, the printer mode
changes to Black only mode and Black only LED glows.
6.2.2.1 Functions
LED function is made up of
- Ready/Printing status display
- Error status display
- Toner low status display
- Black only status display
6.2.2.2 Detail Description
LED control order
1) Control LED according to current printer state
: After the panel task is received each event, the LED operation is controlled by current printer status.
2) Write LED value to GOP (General Output Port)