• Code: H3 0
• Description: Fusing section high temperature trouble (THS1)
• Causes: The fusing temperature rises above 220°C. (The temperature sensor (Thermistor) voltage of 0.85V or less is detected.)
• Remedy: Case 1 Trouble position/cause Temperature sensor (Thermistor) trouble Remedy (Check) Check for dirt on the temperature sensor (Thermistor). (Repair) Clean or replace the temperature sensor (Thermistor). / SIM 14 (After-work) Note Case 2 Trouble position/cause PCU SUB PWB trouble Remedy (Check) Check the PCU SUB PWB fusing temperature sensor circuit. (Repair) PCU SUB PWB replacement / SIM 14 (After-work) Note Case 3 Trouble position/cause Heater lamp control PWB (AC SUB PWB) trouble Remedy (Check) Check the operation of the heater lamp. (SIM 5-2) (Repair) Replace the heater lamp control PWB (AC SUB PWB). / SIM 14

• Code: H3 1
• Description: Fusing section high temperature trouble (THS2)
• Causes: The fusing temperature rises above 220°C. (The temperature sensor (Thermistor) voltage of 0.85V or less is detected.)
• Remedy: Case 1 Trouble position/cause Temperature sensor (Thermistor) trouble Remedy (Check) Check for dirt on the temperature sensor (Thermistor). (Repair) Clean or replace the temperature sensor (Thermistor). / SIM 14 (After-work) Note Case 2 Trouble position/cause PCU SUB PWB trouble Remedy (Check) Check the PCU SUB PWB fusing temperature sensor circuit. (Repair) PCU SUB PWB replacement / SIM 14 (After-work) Note Case 3 Trouble position/cause Heater lamp control PWB (AC SUB PWB) trouble Remedy (Check) Check the operation of the heater lamp. (SIM 5-2) (Repair) Replace the heater lamp control PWB (AC SUB PWB). / SIM 14

• Code: H3 2
• Description: Fusing section high temperature trouble (THS3)
• Causes: The fusing temperature rises above 220°C. (The temperature sensor (Thermistor) voltage of 0.85V or less is detected.)
• Remedy: Case 1 Trouble position/cause Temperature sensor (Thermistor) trouble Remedy (Check) Check for dirt on the temperature sensor (Thermistor). (Repair) Clean or replace the temperature sensor (Thermistor). / SIM 14 (After-work) Note Case 2 Trouble position/cause PCU SUB PWB trouble Remedy (Check) Check the PCU SUB PWB fusing temperature sensor circuit. (Repair) PCU SUB PWB replacement / SIM 14 (After-work) Note Case 3 Trouble position/cause Heater lamp control PWB (AC SUB PWB) trouble Remedy (Check) Check the operation of the heater lamp. (SIM 5-2) (Repair) Replace the heater lamp control PWB (AC SUB PWB). / SIM 14

• Code: H3 3
• Description: Fusing section high temperature trouble (THS4)
• Causes: The fusing temperature rises above 220°C. (The temperature sensor (Thermistor) voltage of 0.85V or less is detected.)
• Remedy: Case 1 Trouble position/cause Temperature sensor (Thermistor) trouble Remedy (Check) Check for dirt on the temperature sensor (Thermistor). (Repair) Clean or replace the temperature sensor (Thermistor). / SIM 14 (After-work) Note Case 2 Trouble position/cause PCU SUB PWB trouble Remedy (Check) Check the PCU SUB PWB fusing temperature sensor circuit. (Repair) PCU SUB PWB replacement / SIM 14 Case 3 Trouble position/cause Heater lamp control PWB (AC SUB PWB) trouble Remedy (Check) Check the operation of the heater lamp. (SIM 5-2) (Repair) Replace the heater lamp control PWB (AC SUB PWB). / SIM 14

• Code: H4 0
• Description: Fusing section (upper) low temperature trouble (HL1)
• Causes: The specified temperature is not reached within the specified time (5 min) after starting warm-up.
• Remedy: Case 1 Trouble position/cause Temperature sensor (Thermistor) trouble Remedy (Check) Check for dirt on the temperature sensor (Thermistor). (Repair) Clean or replace the temperature sensor (Thermistor). / SIM 14 (After-work) Note Case 2 Trouble position/cause PCU SUB PWB trouble Remedy (Check) Check the PCU SUB PWB fusing temperature sensor circuit. (Repair) PCU SUB PWB replacement / SIM 14 (After-work) Note Case 3 Trouble position/cause Heater lamp control PWB (AC SUB PWB) trouble Remedy (Check) Check the operation of the heater lamp. (SIM 5-2) (Repair) Replace the heater lamp control PWB (AC SUB PWB). / SIM 14 (After-work) Note Case 4 Trouble position/cause AC main power PWB trouble Remedy (Check) Check the operation of the heater lamp. (SIM 5-2). (Repair) AC main power PWB replacement / SIM 14 (After-work) Note Case 5 Trouble position/cause Interlock switch (door) trouble Remedy (Check) Check the interlock switch (door). (Repair) Replace the interlock switch (door). / SIM 14 (After-work) Note Case 6 Trouble position/cause Thermostat operation or trouble Remedy (Check) Check the thermostat contact. (Repair) Reset or replace the thermostat. / SIM 14 (After-work) Note Case 7 Trouble position/cause Heater lamp trouble Remedy (Check) Check the operation of the heater lamp. (SIM5-2) (Repair) Replace the heater lamp. / SIM 14

• Code: H4 1
• Description: Fusing section (lower) low temperature trouble (HL2)
• Causes: The specified temperature is not reached within the specified time (5 min) after starting warm-up.
• Remedy: Case 1 Trouble position/cause Temperature sensor (Thermistor) trouble Remedy (Check) Check for dirt on the temperature sensor (Thermistor). (Repair) Clean or replace the temperature sensor (Thermistor). / SIM 14 (After-work) Note Case 2 Trouble position/cause PCU SUB PWB trouble Remedy (Check) Check the PCU SUB PWB fusing temperature sensor circuit. (Repair) PCU SUB PWB replacement / SIM 14 (After-work) Note Case 3 Trouble position/cause Heater lamp control PWB (AC SUB PWB) trouble Remedy (Check) Check the operation of the heater lamp. (SIM 5-2) (Repair) Replace the heater lamp control PWB (AC SUB PWB). / SIM 14 (After-work) Note Case 4 Trouble position/cause AC main power PWB trouble Remedy (Check) Check the operation of the heater lamp. (SIM 5-2). (Repair) AC main power PWB replacement / SIM 14 (After-work) Note Case 5 Trouble position/cause Interlock switch (door) trouble Remedy (Check) Check the interlock switch (door). (Repair) Replace the interlock switch (door). / SIM 14 (After-work) Note Case 6 Trouble position/cause Thermostat operation or trouble Remedy (Check) Check the thermostat contact. (Repair) Reset or replace the thermostat. / SIM 14 (After-work) Note Case 7 Trouble position/cause Heater lamp trouble Remedy (Check) Check the operation of the heater lamp. (SIM5-2) (Repair) Replace the heater lamp. / SIM 14

• Code: H5 1
• Description: Paper jam in the fusing/paper exit section
• Causes: POD/DPID do not detect 3 sheets of paper continuously.
• Remedy: Case 1 Trouble position/cause Paper remaining in the fusing section Remedy (Check) Check for remaining paper. (Repair) Remove remaining paper. / SIM 14 (After-work) Note Case 2 Trouble position/cause POD/DPID detector trouble Remedy (Check) Check operations of POD/DPID detectors. (SIM30-1) (Repair) Replace the POD/DPID detectors. / SIM 14 (After-work) Note Case 3 Trouble position/cause Fusing unit installation trouble Remedy (Check) Check installation of the fusing unit. (Repair) Install the fusing unit properly. / SIM 14 Case 4 Trouble position/cause Fusing unit installation trouble Remedy (Check) (Repair) SIM 14 (After-work) Note Case 5 Trouble position/cause PCU SUB PWB trouble Remedy (Check) Check the PCU SUB PWB fusing temperature sensor circuit. (Repair) PCU SUB PWB replacement / SIM 14 (After-work) Note Case 6 Trouble position/cause PCU MAIN PWB trouble Remedy (Check) (Repair) Replace the PCU MAIN PWB. / SIM 14 (After-work) Re-enter setup values and adjustment values. (Install the EEPROM of the defective PCU MAIN PWB to a new PCU MAIN PWB.)

• Code: H5 2
• Description: Paper jam in the fusing/paper exit sections (paper jam winding around the upper fusing roller) (Upper fusing roller temperature distribution abnormality)
• Causes: A difference is generated in the upper roller temperature distribution. (A difference between the detected outputs of the fusing main temperature sensor (THS1) and the sub temperature sensor (THS3) is greater than the specified level. (Winding of paper is detected.)
• Remedy: Case 1 Trouble position/cause Paper is winding around the fusing roller. Remedy (Check) Check for winding jam of paper around the fusing roller. (Repair) Remove paper winding around the fusing roller. / SIM 14 (After-work) Note Case 2 Trouble position/cause Temperature sensor (Thermistor) trouble Remedy (Check) Check for dirt on the temperature sensor (Thermistor). (Repair) Clean or replace the temperature sensor (Thermistor). / SIM 14 (After-work) Note Case 3 Trouble position/cause PCU SUB PWB trouble Remedy (Check) Check the PCU SUB PWB fusing temperature sensor circuit. (Repair) PCU SUB PWB replacement / SIM 14