• 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.s installed. 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.s installed. 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.
• 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
  bsence 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.

• Code: 7601
• Description: ID sensor 1 (front) error
• Causes: Defective ID sensor. Defective PWB.
• Remedy: Defective ID sensor. Replace the ID sensor 1.
  Defective PWB. Replace the engine PWB check for correct operation.

• Code: 7602
• Description: ID sensor 2 (rear) error
• Causes: Defective ID sensor. Defective PWB.
• Remedy: Defective ID sensor. Replace the ID sensor 2.
  Defective PWB. Replace the engine PWB check for correct operation.

• Code: 7611
• Description: ID sensor (K) density error
  When the concentration in a bias calibration is unusual.
• Causes: Defective ID sensor. Defective PWB.
• Remedy: Defective ID sensor. Replace the ID sensor.
  Defective PWB. Replace the engine PWB check for correct operation.