Xerox Phaser 3100MFP Service Manual page 211

General Procedures and Information
Block Diagram
Figure 2
The Engine Board controls the laser diode power (APCSH) and transfers data for printing to the
laser diode (VIDEO). As an electrical safety feature, there is an interlock switch on the Engine
Board. This switch cuts +24 volts whenever the front door is opened.
Error Conditions
Laser Error
The machine detects laser synchronization signal pulses (PGSYCI) 70 milliseconds after the
(LDENA) signal is sent. It detects a laser error if the pulse count does not reach the specified
number within 400 milliseconds.
When this occurs, the machine displays an error on the LCD panel (Error 56).
Polygon Mirror Motor Error
The machine detects a polygon mirror motor error when the (PMLOK) signal does not go low with-
in 3.5 seconds of the (PMENA) signal. When this occurs, the machine displays an error on the
LCD panel (Error 57).
Phaser 3100 MFP 04/08 6-63