• Code: C7210
• Description: Short-circuited internal thermistor • The thermistor input value is 0.5 V or less.
• Causes: Poor contact in the connector terminals. Defective developing humidity sensor.Defective engine PWB.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC23 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective developing humidity sensor. Replace the developing humidity sensor. Defective engine PWB. Replace the engine PWB.

• Code: C7300
• Description: Toner hopper problem • During toner replenishment after toner empty has been detected, toner empty could not be cleared in 3 times of 360 s.
• Causes: Defective toner level detection sensor. Poor contact in the toner level detection sensor connector terminals.
• Remedy: Defective toner level detection sensor. Replace the toner level detection sensor. Poor contact in the toner level detection sensor connector terminals. Check the connection of connectors YC2 and YC5 on the deck PWB and YC3 on the engine PWB. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable.

• 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 YC13 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective humidity sensor. Replace the humidity sensor.

• Code: C7810
• Description: Short-circuited external thermistor • The thermistor input value is 0.5 V or less.
• Causes: Poor contact in the connector terminals. Defective humidity sensor. Defective engine PWB.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC13 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective humidity sensor. Replace the humidity sensor. Defective engine PWB. Replace the engine PWB.

• Code: C8010
• Description: Document finisher paper conveying motor problem • The LOCK signal of the paper conveying motor is detected for more than 500 ms while the paper conveying motor is operating. However, the first 1 s after the paper conveying motor is turned on is excluded from detection.
• Causes: Loose connection of the paper conveying motor connector. Defective paper conveying motor. Defective finisher main PWB.
• Remedy: Loose connection of the paper conveying motor connector. Check the connection of connector YC14 on the finisher main PWB. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Defective paper conveying motor. Replace the paper conveying motor and check for correct operation. Defective finisher main PWB. Replace the finisher main PWB and check for correct operation.

• Code: C8020
• Description: Document finisher punch motor problem • The LOCK signal of the punch motor is detected for more than 500 ms while the punch motor is operating. However, the first 1 s after the punch motor is turned on is excluded from detection.
• Causes: Loose connection of the punch motor connector. Defective punch motor. Defective finisher main PWB.
• Remedy: Loose connection of the punch motor connector. Check the connection of connector YC13 on the finisher main PWB and YC1 on the punch PWB. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Defective punch motor. Replace the punch motor and check for correct operation. Defective finisher main PWB. Replace the finisher main PWB and check for correct operation.

• Code: C8030
• Description: Document finisher upper paper conveying belt problem • During initialization, the intermediate tray upper sliding plate is not detected in the home position within 3 s after the belt returns to the home position. JAM87 is indicated the first time this problem occurs. If the problem reoccurs after initialization when the front cover is opened and closed, the problem is in the upper paper conveying belt. • When the intermediate tray upper sliding plate is operated from the home position, the upper paper conveying belt home position sensor does not turn off within 1 s.
• Causes: Phase shift of the upper paper conveying belt. Malfunction of the upper paper conveying belt motor. Malfunction of the upper paper conveying belt home position sensor. Loose connection of the upper paper conveying belt home position sensor connector. Incorrect insertion of the intermediate tray. Defective finisher main PWB.
• Remedy: Phase shift of the upper paper conveying belt. Correct the phase of the upper paper conveying belt and check for correct operation. Malfunction of the upper paper conveying belt motor. Replace the upper paper conveying belt motor and check for correct operation. Malfunction of the upper paper conveying belt home position sensor. Replace the upper paper conveying belt home position sensor and check for correct operation. Loose connection of the upper paper conveying belt home position sensor connector. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Incorrect insertion of the intermediate tray. Check whether the intermediate tray catches are damaged. Defective finisher main PWB. Replace the finisher main PWB and check for correct operation.

• Code: C8040
• Description: Document finisher lower paper conveying belt problem • During initialization, the intermediate tray lower sliding plate is not detected in the home position within 3 s after the belt returns to the home position. JAM87 is indicated the first time this problem occurs. If the problem reoccurs after initialization when the front cover is opened and closed, the problem is in the lower paper conveying belt. • When the intermediate tray lower sliding plate is operated from the home position, the lower paper conveying belt home position sensor does not turn off within 1 s.
• Causes: Phase shift of the lower paper conveying belt. Malfunction of the lower paper conveying belt motor. Malfunction of the lower paper conveying belt home position sensor. Loose connection of the lower paper conveying belt home position sensor connector. Incorrect insertion of the intermediate tray. Defective finisher main PWB.
• Remedy: Phase shift of the lower paper conveying belt. Correct the phase of the lower paper conveying belt and check for correct operation. Malfunction of the lower paper conveying belt motor. Replace the lower paper conveying belt motor and check for correct operation. Malfunction of the lower paper conveying belt home position sensor. Replace the lower paper conveying belt home position sensor and check for correct operation. Loose connection of the lower paper conveying belt home position sensor connector. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Incorrect insertion of the intermediate tray. Check whether the intermediate tray catches are damaged. Defective finisher main PWB. Replace the finisher main PWB and check for correct operation.