HP LaserJet Pro M402d

DC controller
The DC controller controls the operation of the printer and its components. The DC controller starts the
printer operation when the printer power is turned on and the power supply sends DC voltage to the DC
controller. After the printer enters the standby period, the DC controller sends out various signals to operate
motors, solenoids, and other printer components based on the print command and image data that the host
computer sends.
Figure 1-3 DC controller block diagram
Transfer roller
High-voltage
power supply
Fan
Cartridge
LED
Motor
Clutch
Solenoid
Switch
Photointerrupter
Formatter
Control panel
Accessory
Laser scanner ass’y
Fuser
AC input
Low-voltage
power supply
DC controller
Switch
Sensor
Component type Abbreviation Description
Motor M1 Fuse motor
M3 Scanner motor
Fan Fm1 Main fan
6 Chapter 1 Theory of operation ENWW