• Code: C7400
• Description: Image formation unit connector insertion problem
  • Absence of the image formation unit is detected continuously for 1500 ms while there is no error on the copier.
• Causes: Image formation unit connector inserted incorrectly. Defective image formation unit connector.
• Remedy: Reinsert the image formation unit connector if necessary. Replace the image formation unit.

• Code: C7410
• Description: Drum unit connector insertion problem
  • Absence of the drum unit is detected continuously for 1500 ms while there is no error on the copier.
• Causes: Drum unit connector inserted incorrectly. Defective drum unit connector.
• Remedy: Reinsert the drum unit connector if necessary. Replace the drum unit.

• Code: C7800
• Description: Broken external temperature thermistor wire
  • The input voltage is above 4.5 V.
• Causes: Poor contact in the humidity sensor PCB connector terminals. Defective external temperature thermistor.
• Remedy: Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Replace the humidity sensor PCB.

• Code: C7810
• Description: Short-circuited external temperature thermistor • The input voltage is below 1.0 V.
• Causes: Poor contact in the humidity sensor PCB connector terminals. Defective external temperature thermistor.
• Remedy: Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Replace the humidity sensor PCB.

• Code: C8010
• Description: Finisher paper conveying motor problem
  • The paper conveying motor lockup signal is detected for 0.5 s or longer.
• Causes: Poor contact in the paper conveying motor connector terminals. The paper conveying motor malfunctions. Defective finisher main PCB.
• Remedy: Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Replace the paper conveying motor and check for correct operation. Replace the finisher main PCB and check for correct operation.

• Code: C8030
• Description: Finisher paper conveying belt problem
  • An on-to-off or off-to-on state change of the paper conveying belt home position sensor is not detected within 2 s of the paper conveying belt clutch turning on.
• Causes: The paper conveying belt is out of phase. The paper conveying belt clutch malfunctions. The paper conveying belt home position sensor malfunctions. The paper conveying belt home position sensor connector makes poor contact. The internal tray is incorrectly inserted.
• Remedy: Adjust the paper conveying belt so that it is in phase and check for correct operation. Replace the paper conveying belt clutch and check for correct operation. Replace the paper conveying belt home position sensor and check for correct operation. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Check whether the internal tray unit or front cover catches are damaged.

• Code: C8140
• Description: Finisher tray elevation motor problem
  • The sort tray is not detected in the home position within 30 s of the start of the tray elevation motor rotation.
• Causes: Poor contact in the tray elevation motor connector terminals. The tray elevation motor malfunctions. Defective finisher main PCB.
• Remedy: Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Replace the tray elevation motor and check for correct operation. Replace the finisher main PCB and check for correct operation.

• Code: C8170
• Description: Finisher front side registration motor problem
  • If the front side registration home position sensor is on in initialization, the sensor does not turn off within 570 ms of starting initialization.
  • If the front side registration home position sensor is off in initialization, the sensor does not turn on within 3180 ms of starting initialization.
• Causes: The front side registration motor connector makes poor contact. The front side registration motor malfunctions. The front side registration home position sensor connector makes poor contact. The front side registration home position sensor malfunctions. Defective finisher main PCB.
• Remedy: Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Replace the front side registration motor and check for correct operation. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Replace the front side registration home position sensor and check for correct operation. Replace the finisher main PCB and check for correct operation.