HP LaserJet Pro M402d - Page 26

Motor control
The printer has two motors. The motors drive the components in the paper-feed and image-formation
systems.
The DC controller monitors the fuser motor and the scanner motor to determine if a motor has failed. It
noties the formatter when it encounters the following conditions:
●
Startup failure: the motor does not reach a specied speed within a specied time from when the motor
starts.
●
Rotational failure: the rotational speed of the motor is not in the specied range for a specied time
after the motor reaches a specied speed.
Table 1-2 Motors
Abbreviation Name Purpose Failure detection
M1 Fuser motor Drives the pressure roller and delivery roller;
the pressurization and release of the pressure
roller; and the engagement and
disengagement of the primary and secondary
transfer rollers
Yes
M3 Scanner motor Drives the scanner mirror Yes
Fan control
The printer has one fan for preventing the temperature from rising in the printer and for cooling the printed
pages.
The DC controller determines if there is a fan failure and noties the formatter if the fan locks for a specied
time from when the fan starts.
Table
1-3 Fans
Abbreviation Name Cooling area Type Speed
FM1 Main fan Inside of printer Intake Full
8 Chapter 1 Theory of operation ENWW