Printhead Control; Rotation Of Printhead Motor; Determination Of Printhead Ready; Printhead Reference Value - Lexmark W850n Service Manual

Printhead control

Rotation of printhead motor

The on/off control of the printhead motor is performed according to the mode of operation as shown below.
Operation mode
Standby mode
Print mode
Sleep mode

Determination of printhead ready

The printhead goes into ready state after the specified period passes since the reception of the printhead MPA
start signal and the SOS cycle exceeds the reference value.

Printhead reference value

Printhead reference value
Ready reference value
Fail reference value

Fuser control

Fuser control method

The on/off control of the main/sub heater lamps is performed based on the fuser control temperature. The fuser
transmits between the five states (warm up, ready, standby, print, and low power) depending on the heat roll
surface temperature or printer conditions.
The fuser temperature control starts when the fuser ready in the LVPS card assembly is turned on after a preset
time period has passed from power on. If a failure occurs, the heater lamps are turned off, the fuser ready is
turned off, and then the fuser temperature control is stopped.

Main/sub heater lamps on/off control

The center and rear thermistors detect the heat roll surface temperature (fuser temperature) to regulate the
temperature at the target control temperature by turning on or off the main/sub heater lamps.

Fuser warm-up

The fuser warm-up starts at the time of power on, interlock open or close, jam reset, or return from the low power
mode, and ends when the ready temperature is attained, when a failure occurs, or when executing diagnosis.
PRINTHEAD motor on/off
Always off
Turns on upon receiving the signal from the controller,
and turns off after a preset time has passed from the
end of printing. Also turns off if a print command is not
received within 30 seconds from the reception of the
signal.
Always off
SOS signal interval (equivalent to 98% or more of the rated RPM of the
printhead motor)
SOS signal interval (less than 98% of the rated rpm of the printhead
motor)
Description
4024-110
3-45
Diagnostic aids