HP (Hewlett-Packard) 5L (C3941A) Printer User Manual


 
Print Engine Control System
Laser and Scanner Drive
Based on information received from the Formatter, the DC Controller sends signals
to the Laser/Scanner Assembly to modulate the laser diode ON and OFF and to
drive the Laser/Scanner motor. Refer to “Image Formation System,” later in this
chapter for more information.
Paper Motion Monitoring and Control
The DC Controller PCA controls paper motion by continuously monitoring the
various paper sensors and coordinating the timing with the other print processes.
For a detailed explanation of paper movement, and the interaction of photosensors
and solenoid with the paper movement process, refer to the section “Paper Feed
System,” later in this chapter.
+12 V Shutoff Switch
The 12 volt dc power shutoff switch, Switch 101, located on the top of the printer, is
activated by the printer door. The front door must be closed before the printer can
resume printing.
Engine Test Switch
The Test Print, Switch 201, located on the DC Controller, is activated manually
through an access hole at the front of the printer. This switch causes the print engine
to perform a self-test diagnostic which bypasses the Formatter PCA and prints a full
page of black vertical lines. This test is useful for troubleshooting printer problems
because it isolates the print engine from the Formatter PCA. (See Chapter 7,
“Troubleshooting,” to learn more about how to perform an engine test.)
Motor
The Motor is controlled by the DC Controller PCA. The Motor provides all of the
printer’s paper movement.
Functional Overview 5 - 5