Fixing Unit Failure Detection - Canon imageCLASS MF269dw Service Manual

DC Controller
The DC Controller monitors temperature of the Thermistor at all time. When abnormal temperature is detected, the DC
Controller stops the output of Fixing Heater control signal, and turns OFF relays (RL101) to shut off the power supply to the
Fixing Heater.
Fixing Heater safety circuit
Fixing Heater safety circuit monitors temperature of the Thermistor at all time. When abnormal temperature is detected, the
Fixing Heater turns OFF relays (RL101) to shut off the power supply to the Fixing Heater.
Thermoswitch
When the temperature of the Fixing Heater rises abnormally high, the Thermoswitch opens to shut off the power supply to the
Fixing Heater.
Down Sequence Control
When the temperature of the Fixing Heater exceeded the threshold value, the machine delivers paper being printed, drives the
fan and repeats the stopped state (approx. 30 seconds) and 50% reduced productivity state to decrease the temperature.
*1: Number of sheets corresponding to 50% productivity with LTR (approx. 18 sheets, 1-suded) are fed.

Fixing Unit Failure Detection

Overview
The DC Controller shuts down the power supply to the Fixing Unit and notifies an error when the Fixing Unit is in the following
condition.
• Startup failure
• Abnormal high temperature failure
• Abnormal low temperature failure
• Fixing drive circuit error
Description
Fixing Unit startup failure
An error code is notified if the Fixing Unit does not reach a certain temperature within a specified period of time.
Abnormal high temperature failure
An error code is notified if an abnormally high temperature is detected in the Fixing Unit.
Abnormal low temperature failure
An error code is notified if an abnormally low temperature is detected in the Fixing Unit.
Fixing Unit drive circuit error
An error code is notified if an abnormality is detected in the Fixing Unit drive circuit.
Error Code
E000: Startup failure
• E000-0000: Fixing Unit startup failure
E001: Abnormal high temperature failure
• E001-0000: Abnormal high temperature of Fixing Unit
E003: Abnormal low temperature failure
• E003-0000: Abnormal low temperature of Fixing Unit
E004: Fixing drive circuit error
• E004-0000: Fixing Heater drive circuit error
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2. Technology