Fuser Fan - Lexmark W820 Service Manual

4025-XXX
Thermistor (STS)
The Thermistor monitors the surface temperature of the Hot Roll and sends information
back to the MCU PWB through the I/O PWB. According to the temperature information
received, the MCU PWB commands the AC Driver PWB to either switch on or switch off
the Heat Lamps. The Thermistor is marked STS on the circuit schematic.
Heat Lamp Main
Logic on the MCU uses the /MAIN HEAT signal the AC Drive to apply 110VC to switch on
the Main Heat Lamp.
Heat Lamp Sub
Logic on the MCU uses the /SUB HEAT signal the AC Drive to apply 110VC to switch on
the Sub Heat Lamp.

Fuser Fan

The MCU PWB controls the Fuser Fan and the alarm signal that indicates the Fan is not
rotating.
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Service Manual