- Hewlett-Packard Printers Service Manual

5-12 Functional Information
Laser and Scanner Drive
Based on information received from the Formatter, the Engine
Controller Board sends signals to the Laser Scanner Assembly to
modulate the Laser Diode on and off and to drive the Laser Scanner
motor. See “Image Formation System” on page 5-22 for more
information.
Paper Motion Monitoring and Control
The Engine Controller Board controls paper motion by continuously
monitoring the various Paper Sensors and coordinating paper
movement with the other print processes. For more information, see
“Paper Feed System” on page 5-33.
Solenoids, Sensors, Clutches, and Switches
See “Engine Controller Board Inputs and Outputs” on page 5-8.
Engine Test Print
See “Engine Test” on page 7-11.