• Code: 7902
• Description: Drum C EEPROM error
  Reading from or writing to EEPROM cannot be performed.
• Causes: Poor contact in the connector terminals. Defective drum PWB C.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC17 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective drum PWB C. Replace the drum unit C.

• Code: 7903
• Description: Drum M EEPROM error
  Reading from or writing to EEPROM cannot be performed.
• Causes: Poor contact in the connector terminals. Defective drum PWB M.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC17 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective drum PWB M. Replace the drum unit M.

• Code: 7904
• Description: Drum Y EEPROM error
  Reading from or writing to EEPROM cannot be performed.
• Causes: Poor contact in the connector terminals. Defective drum PWB Y.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC18 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective drum PWB Y. Replace the drum unit Y.

• Code: 7911
• Description: Developing unit BK EEPROM error
  Reading from or writing to EEPROM cannot be performed.
• Causes: Poor contact in the connector terminals. Defective developing PWB BK.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC18 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective developing PWB BK. Replace the developing unit BK.

• Code: 7912
• Description: Developing unit C EEPROM error
  Reading from or writing to EEPROM cannot be performed.
• Causes: Poor contact in the connector terminals. Defective developing PWB C.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC17 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective developing PWB C. Replace the developing unit C.

• Code: 7913
• Description: Developing unit M EEPROM error
  Reading from or writing to EEPROM cannot be performed.
• Causes: Poor contact in the connector terminals. Defective developing PWB M.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC17 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective developing PWB M. Replace the developing unit M.

• Code: 7914
• Description: Developing unit Y EEPROM error
  Reading from or writing to EEPROM cannot be performed.
• Causes: Poor contact in the connector terminals. Defective developing PWB Y.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC18 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective developing PWB Y. Replace the developing unit Y.

• Code: 8020
• Description: Punch motor problem (optional 3000- sheet document finisher)
  The LOCK signal of the punch motor is detected for more than 500 ms while the punch motor is operating.
• Causes: Poor contact in the connector terminals. Defective punch motor. Defective PWB.
• Remedy: Poor contact in the connector terminals. Check the connection of connector on the punch PWB and the continuity across the connector terminals. Repair or replace if necessary.
  Defective punch motor. Replace the punch motor.
  Defective PWB. Replace the punch PWB or finisher main PWB and check for correct operation.