Brother HL-3450CN Service Manual page 131

CHAPTER 5 CONTROL PANEL OPERATION
3) Press the Go button to implement the SW TEST.
The following display appears on the LCD and the LEDs are all turned off.
Check that the LEDs are turned on and the corresponding number appears as follows
when pressing the buttons on the control panel in order.
4) Press the Go button to implement the SENSOR TEST.
The following display appears on the LCD.
Check that the display of each sensor is changed to the corresponding character.
NOTE:
x
X X X X X X X X
1 2 3 4 5 6 7 8
ABCDEFGHIJKLMNOP
QRST
For the sensor of 'Q' for HL-3450CN, the display is not changed to 'Q' and stays .
Corresponding button number on the panel
3
6
Corresponding sensor code
5-6
1 2
4
5
7
8