• Code: C7410
• Description: Drum unit connector insertion problem Absence of the drum unit is detected.
• Causes: Drum unit connector inserted incorrectly.
  Defective drum unit connector.
• Remedy: Drum unit connector inserted incorrectly. Reinsert the drum unit connector if necessary.
  Defective drum unit connector. Replace the drum unit.

• Code: C7800
• Description: Broken external thermistor wire
  The thermistor output value is 4.5 V or more.
• Causes: Poor contact in the connector terminals.
  Defective humidity sensor
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC10 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective humidity sensor. Replace the humidity sensor.

• Code: C7900
• Description: Drum EEPROM error
  Reading from or writing to EEPROM cannot be performed.
• Causes: Poor contact in the connector terminals.
  Defective drum unit.
• Remedy: Poor contact in the connector terminals. Check the connection of connector on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective drum unit. Replace the drum unit.

• Code: C7910
• Description: Developing unit EEPROM error
  Reading from or writing to EEPROM cannot be performed.
• Causes: Poor contact in the connector terminals
  Defective developing unit.
• Remedy: Poor contact in the connector terminals. Check the connection of connector on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective developing unit. Replace the developing unit.

• Code: C8030
• Description: Tray upper limit detection problem (optional document finisher)
  When the tray elevation motor raises a tray, the ON status of the tray upper limit sensor is detected.
• Causes: The tray upper limit sensor, paper surface sensor 1/2 connector makes poor contact.
  Defective tray upper limit sensor, paper surface sensor 1/2.
  Defective finisher main PWB.
• Remedy: The tray upper limit sensor, paper surface sensor 1/2 connector makes poor contact. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable.
  Defective tray upper limit sensor, paper surface sensor 1/2. Replace the sensor.
  Defective finisher main PWB. Replace the finisher main PWB and check for correct operation.

• Code: C8040
• Description: Belt problem (optional document finisher)
  The belt sensor does not turn on/off within specified time of the belt solenoid turning on.
• Causes: The belt sensor, belt solenoid connector makes poor contact.
  Defective belt sensor.
  Defective belt solenoid.
  Defective finisher main PWB.
• Remedy: The belt sensor, belt solenoid connector makes poor contact. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable.
  Defective belt sensor. Replace the belt sensor.
  Defective belt solenoid. Replace the belt solenoid.
  Defective finisher main PWB. Replace the finisher main PWB and check for correct operation.

• Code: C8140
• Description: Tray elevation motor problem (optional document finisher)
  The tray low limit sensor or paper surface sensor 1/2 cannot be detected to be on within 10 s since the tray elevation motor is activated.
• Causes: The tray elevation motor connector makes poor contact.
  The tray elevation motor malfunctions.
  The tray lower limit sensor, paper surface sensor 1/2 connector makes poor contact.
  Defective tray lower limit sensor, paper surface sensor 1/2.
  Defective finisher main PWB.
• Remedy: The tray elevation motor connector makes poor contact. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable.
  The tray elevation motor malfunctions. Replace the tray elevation motor.
  The tray lower limit sensor, paper surface sensor 1/2 connector makes poor contact. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable.
  Defective tray lower limit sensor, paper surface sensor 1/2. Replace the sensor.
  Defective finisher main PWB. Replace the finisher main PWB and check for correct operation.

• Code: C8170
• Description: Finisher front side registration motor problem (optional built-in finisher)
  When the front-side registration home-position sensor is turned on during initialization, the sensor did not turn on while it has moved by 106 pulses. When the front-side registration home-position sensor is turned off during initialization, the sensor did not turn on in 3 s.
• Causes: The front side registration motor connector makes poor contact.
  Defective front side registration motor.
  The front side registration home position sensor connector makes poor contact.
  Defective front side registration home position sensor.
  Defective finisher control PWB.
• Remedy: The front side registration motor connector makes poor contact. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable.
  Defective front side registration motor. Replace front side registration motor.
  The front side registration home position sensor connector makes poor contact. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable.
  Defective front side registration home position sensor. Replace the front side registration home position sensor.
  Defective finisher control PWB. Replace the finisher control PWB and check for correct operation.