Fixing Assembly Failure Detection - Canon LBP351 Series Service Manual

3. Thermoswitch
When the temperature of the Fixing Heater rises abnormally and the Thermoswitch (TP1) exceeds a certain temperature,
the contact of the Thermoswitch is disconnected to shut down the power supply to the Fixing Assembly.
● Fixing Assembly failure detection
When the machine is under the following conditions, the DC Controller shuts down the power supply to the Fixing Assembly and
notifies an error.
1. Fixing temperature rising error
Temperature of the thermistor does not rise although a specified period of time has passed since the heater was turned ON.
<Related error codes>
• E000-0000: Temperature of the Main Thermistor did not become a certain temperature although the specified time had
passed
2. Abnormally high fixing temperature detection
When a Thermistor reaches a certain temperature or higher, it is judged as abnormal high temperature for the thermistor.
<Related error codes>
• E001-0000: The Main Thermistor detected a temperature higher than a certain temperature.
• E001-0001: The Sub Thermistor detected a temperature higher than a certain temperature.
3. Abnormally low fixing temperature detection
After it was detected that the temperature of the Fixing Main Thermistor was 100 deg C or higher while the Fixing Heater
was ON, a temperature lower than a certain temperature was detected.
<Related error codes>
• E003-0000: Temperature of the Main Thermistor was lower than a certain temperature although a specified period of
time has passed since the heater was turned ON.
• E003-0001: Temperature of the Sub Thermistor 1 was lower than a certain temperature although a specified period of
time has passed since the heater was turned ON.
4. Fixing drive circuit error
When the DC Controller cannot detect a specific frequency, a fixing drive circuit failure is judged to have occurred.
<Related error codes>
• E004-0000: Error in either the Fixing Heater or the Fixing Motor
5. Fixing Assembly detection
The printer detects the Fixing Assembly when the main power is turned on and when operation starts.
The DC Controller monitors the Fixing Assembly detection signal to detect the presence of the Fixing Assembly.
Consequently, when the DC Controller determines that the Fixing Assembly is not connected, it outputs a warning message.
6. Power supply type detection
This machine does not perform detection of the fixing type based on power supply differences.
■ Fixing Life Detection
The life of the Fixing Assembly is detected to prevent fixing errors due to the Fixing Assembly having reached the end of life.
This machine has a counter in the controller to determine the life of the Fixing Assembly.
• SERVICEMODE > COUNTER GR. > FIXER COUNTER
When the above counter value reaches 225,000 sheets, the following message is displayed on the Control Panel and the alarm
code is recorded in the log.
Control Panel display: E5 Prepare fixing unit.
Alarm code: 06-0002 Fixing Assembly warning alarm
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2. Technical Explanation (Device)