• Code: 7402
• Description: Developer unit C type mismatch error
  Absence of the developer unit C is detected.
• Causes: Defective connector cable or poor contact in the connector. Different type of the developer unit is installed.
• Remedy: Defective connector cable or poor contact in the connector. Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. Developer unit C and drum connect PWB (YC7) Drum connect PWB and engine PWB (YC4)
  Different type of the developer unit is installed. Install the correct developer unit.

• Code: 7403
• Description: Developer unit M type mismatch error
  Absence of the developer unit M is detected.
• Causes: Defective connector cable or poor contact in the connector. Different type of the developer unit is installed.
• Remedy: Defective connector cable or poor contact in the connector. Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. Developer unit M and drum connect PWB (YC8) Drum connect PWB and engine PWB (YC4)
  Different type of the developer unit is installed. Install the correct developer unit.

• Code: 7404
• Description: Developer unit Y type mismatch error
  Absence of the developer unit Y is detected.
• Causes: Defective connector cable or poor contact in the connector. Different type of the developer unit is installed.
• Remedy: Defective connector cable or poor contact in the connector. Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. Developer unit Y and drum connect PWB (YC6) Drum connect PWB and engine PWB (YC4)
  Different type of the developer unit is installed. Install the correct developer unit.

• Code: 7411
• Description: Drum unit K type mismatch problem
  Absence of the drum unit K is detected.
• Causes: Drum unit connector inserted incorrectly. Different type of the drum unit is installed.
• Remedy: Drum unit connector inserted incorrectly. Reinsert the drum unit K connector if necessary.
  Different type of the drum unit is installed. Install the correct drum unit.

• Code: 7412
• Description: Drum unit C type mismatch problem
  Absence of the drum unit C is detected.
• Causes: Drum unit connector inserted incorrectly. Different type of the drum unit is installed.
• Remedy: Drum unit connector inserted incorrectly. Reinsert the drum unit C connector if necessary.
  Different type of the drum unit is installed. Install the correct drum unit.

• Code: 7413
• Description: Drum unit M type mismatch problem
  Absence of the drum unit M is detected.
• Causes: Drum unit connector inserted incorrectly. Different type of the drum unit is installed.
• Remedy: Drum unit connector inserted incorrectly. Reinsert the drum unit M connector if necessary.
  Different type of the drum unit is installed. Install the correct drum unit.

• Code: 7414
• Description: Drum unit Y type mismatch problem
  Absence of the drum unit Y is detected.іі
• Causes: Drum unit connector inserted incorrectly. Different type of the drum unit is installed.
• Remedy: Drum unit connector inserted incorrectly. Reinsert the drum unit Y connector if necessary.
  Different type of the drum unit is installed. Install the correct drum unit.

• Code: 7420
• Description: Transfer belt unit type mismatch problem
  Absence of the transfer belt unit is detected.
• Causes: Transfer belt unit connector inserted incorrectly. Different type of the transfer belt unit is installed.
• Remedy: Transfer belt unit connector inserted incorrectly. Reinsert the transfer belt unit connector if necessary.
  Different type of the transfer belt unit is installed. Install the correct transfer belt unit.