• Code: C7710
• Description: Offset drum sensor detection error • When the drum home position is to be detected, the input level from the offset drum sensor to ASIC (U7) of the engine controller PCB has been gone low for 4 seconds.
• Causes: Defective drum PCB. Defective engine controller PCB. Defective harness between engine controller PCB and drum unit, or poor contact of the connector terminals.
• Remedy: Replace the drum unit. Replace the engine controller PCB. Check the continuity of the harness and the insertion of connectors.

• Code: C7800
• Description: Broken external temperature thermistor wire • The thermistor output value is 3.8 V or more for 500 ms continuously.
• Causes: Defective engine controller PCB. Defective humidity/ temperature sensor.
• Remedy: Replace the engine controller PCB and check for correct operation. Replace the humidity/temperature sensor.

• Code: C7810
• Description: Short-circuited external temperature thermistor • The thermistor input value is 0.4 V or less for 500 ms continuously.
• Causes: Defective engine controller PCB. Defective humidity/ temperature sensor.
• Remedy: Replace the engine controller PCB and check for correct operation. Replace the humidity/temperature sensor.

• Code: C8000
• Description: Document finisher incorrect type problem • The cdocument finisher of the type other than the finishers supported by this machine is connected.
• Causes: Defective scanner main PCB. The document finisher of the different type is connected.
• Remedy: Replace the scanner main PCB and check for correct operation. Install the proper type of the document finisher.

• Code: C8010
• Description: Document 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: Document 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: Document 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: Document 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.