Lexmark XM1135, Service Manual

Page: 476 / 510

MPF sensor
Detects the presence of media in the MPF tray.
Media present sensor
Detects the presence of media in the tray.
Tray present sensor
Detects the presence of the tray in the printer.
Bin full sensor
Detects whether the standard bin is full by moving the actuator up and down.
Toner density sensor
Detects a preplaced toner patch and image on the photoconductor (drum) and outputs pulses when the central
line of the patch image aligns with the central line of the detector. The sensor outputs pulses at the timing the
patch image passes the sensor. Therefore, observing changes of intervals at which pulses are output leads to
toner density detection.
Pass through sensor (option tray)
Detects when the media from the option tray passes. This will trigger the pick roller to pick the next media.
Front door sensor
Is a safety switch to cut off a 24 V DC power supply from the LVPS card assembly to the HVPS card assembly,
printer system card assembly and to the main drive motor assembly, while the printer front door assembly is
open.
Other key components
Cooling fan
Discharges air from the printer to prevent excessive temperature increase.
Power supply
The power supply has two main sections: the HVPS and LVPS. The HVPS card assembly generates AC power
and feeds it to the developer roll, the transfer roll assembly and the charge roll assembly. The LVPS card
assembly generates low voltages: 5 V DC for logic circuits, 5 V DC for laser diodes, and 24 V DC for cooling
fans.
Controller board
Controls the printing operation based on the communication with the RIP controller and optional peripherals.
It also controls the fuser, toner dispensing, sensor switch feedback, drive motors, clutches, and solenoids.
7015
Theory of operation
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