Fusing Unit Center Thermistor Defect - Xerox WorkCentre 5021 Service Documentation

010-311 Fusing Unit Center Thermistor Defect

BSD-ON:CH10.2
An open circuit abnormality (the AD value of the STS is equivalent to the open circuit value) of
the Heat Roll Center Thermistor was detected.
Procedure
Turn OFF the power and disconnect the Heat Roll Center Thermistor connector P/J600. Mea-
sure the resistance between the Heat Roll Center Thermistor
the resistance infinite?
Y N
Reconnect the connector P/J600
PWB J403 pin-1 and J403 pin-2. Is the resistance infinite?
Y N
Replace the ESS/MCU PWB.
Check the following connections for open circuits and poor contacts.
• Between ESS/MCU PWB J403-1 and Heat Roll Center Thermistor P600-4
• Between ESS/MCU PWB J403-2 and Heat Roll Center Thermistor P600-3
Replace the Fusing Unit. (PL 7.1)
010-312 Fusing Unit Rear Thermistor Defect
BSD-ON:CH10.2
An open circuit abnormality (the AD value of the STS is equivalent to the open circuit value) of
the Heat Roll Rear Thermistor was detected.
Procedure
Turn OFF the power and disconnect the Heat Roll Rear Thermistor connector P/J600. Mea-
sure the resistance between the Heat Roll Rear Thermistor
resistance infinite?
Y N
Reconnect the connector P/J600
PWB J403 pin-3 and J403 pin-4. Is the resistance infinite?
Y N
Replace the ESS/MCU PWB.
Check the following connections for open circuits and poor contacts.
• Between ESS/MCU PWB J403-3 and Heat Roll Rear Thermistor P600-2
• Between ESS/MCU PWB J403-4 and Heat Roll Rear Thermistor P600-1
Replace the Fusing Unit. (PL 7.1)
Initial Issue
WorkCentre 5021/5019
J600 pin-1 and J600
and measure the resistance between the ESS/MCU
(PL 18.1)
J600 pin-3 and J600
and measure the resistance between the ESS/MCU
(PL 18.1)
010-320 Over Heat Temperature Fail
BSD-ON:CH10.2, CH10.1
A high temperature error was detected at the Center Thermistor (245 degrees C or higher) or
the Rear Thermistor (270 degrees C or higher).
NOTE: To clear this Fail, first remove the cause, next clear the value of NVM [744-040] (Over
Heat Temp Fail) to '0', and then turn the power OFF then ON. The relationship between the dis-
played value and the Thermistor that detected the high temperature error is as follows:
pin-2. Is
• 0: Normal
• 1: High Temperature Error of Heat Roll Center Thermistor
• 2: High Temperature Error of Heat Roll Rear Thermistor
Cause/Action
Check the following:
• The Center Thermistor or the Rear Thermistor for dropped parts, sensor contamination,
and foreign substances blocking the sensor.
• The Heat Roll for wound up, stuck paper.
• The Heat Roll Center Thermistor (Analog Monitor [010-050]) for operation failure.
• The Heat Roll Rear Thermistor (Analog Monitor [010-051]) for operation failure.
• The Heater Rod for operation failure.
If no problem is found, replace the following parts in sequence:
• Fusing Unit (PL 7.1)
• LVPS (PL 18.1)
• ESS/MCU PWB (PL
010-327 Fusing Unit On Time Fail
pin-4. Is the
BSD-ON:CH10.2, CH10.1
Any of the following was detected:
• The Heater Rod did not turn OFF within the specified time after the Heater Rod On.
• After power ON, the temperature of the Fusing Unit does not reach the specified value
within the specified time.
Cause/Action
Check the following:
• The Heater Rod for operation failure.
• The connection between the LVPS
poor contact
• The Center Thermistor for dropped parts, sensor contamination, and foreign substances
blocking the sensor.
• The Heat Roll for wound up, stuck paper.
08/2012
2-17
18.1)
J511 and the Fusing Unit P10 for open circuit and
Status Indicator RAPs
010-311, 010-320