Canon imageCLASS X LBP1238, Service Manual

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DC Controller PCB
The DC Controller PCB monitors the thermistor temperature of the Fixing Heater (Center).
When it exceeds the specified temperature, it is judged that the temperature of the Fixing Assembly is abnormally high, and
the fixing control signal (FSRD) output is stopped, the relay is turned OFF, and the power supply to the heater is turned OFF.
Fixing Heater safety circuit
The Fixing Heater safety circuit monitors the thermistor temperature of the Fixing Heater (Center).
When it exceeds the specified temperature, it is judged that the temperature of the Fixing Assembly is abnormally high, and
the relay is turned OFF and the power supply to the heater is turned OFF.
Thermo Switch
If the temperature of the Fixing Heater rises abnormally and it exceeds the specified temperature, contact point of the Thermo
Switch is opened and the power supply to the heater is turned OFF.
Down sequence control
The DC Controller monitors the thermistor temperature of Fixing Heater. If it rises above the specified temperature due a
case such as the continuous printing of small size paper, the productivity may be greatly lowered (depending on Paper
Settings, lower to approx. 4 page/min for B5/A5/A6/EXEC and approx. 6 pages/min for envelopes) to limit the temperature
rise.
Fixing Assembly Failure Detection
Overview
When the machine is under the following conditions, the DC Controller shuts down the power supply to the Fixing Assembly and
notifies an error.
• Startup failure
• Abnormal high temperature failure
• Abnormal low temperature failure
• Fixing control circuit failure
Description
Fixing Assembly startup failure
An error code is notified if the Fixing Assembly 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 Assembly.
Abnormal low temperature failure
An error code is notified if an abnormally low temperature is detected in the Fixing Assembly.
Fixing control circuit failure
An error code is notified if a zero cross signal is not detected for the specified period of time or more.
Error Code
• E000-0000: Fixing Assembly startup failure
• E001-0000: Abnormal high temperature of Fixing Assembly
• E003-0000: Abnormal low temperature of Fixing Assembly
• E004-0000: Fixing control circuit failure
2. Technical Explanation (Device)
35