• Code: 6600
• Description: Belt rotation error
  The belt was detected to stop for 2 s continuously during motor remote is on.
• Causes: Defective fuser motor. Defective IH belt. Defective IH PWB. Defective PWB.
• Remedy: Defective fuser motor. Replace the fuser motor.
  Defective IH belt. Replace the fuser unit.
  Defective IH PWB. Replace the IH PWB and check for correct operation.
  Defective PWB. Replace the engine PWB and check for correct operation.

• Code: 6710
• Description: CPU thermal runaway (IHPWB)
• Causes: Defective PWB.
• Remedy: Replace the IH PWB and check for correct operation.

• Code: 6720
• Description: Belt rotation error (IHPWB)
• Causes: Defective PWB. Defective fuser motor.PWB). Defective fuser unit.
• Remedy: Defective PWB. Replace the IH PWB and check for correct operation.
  Defective fuser motor. Replace the fuser motor.
  Defective fuser unit. Replace the fuser unit.

• Code: 6730
• Description: Abnormally high IGBT1 temperature (IHPWB)
• Causes: Defective PWB. Defective cooling fan motor.
• Remedy: Defective PWB. Replace the IH PWB and check for correct operation.
  Defective cooling fan motor. Replace the IH fan motor.

• Code: 6740
• Description: Abnormally high IGBT2 temperature (IHPWB)
• Causes: Defective PWB. Defective cooling fan motor.
• Remedy: Defective PWB. Replace the IH PWB and check for correct operation.
  Defective cooling fan motor. Replace the IH fan motor.

• Code: 6750
• Description: Abnormally output overcurrent (IHPWB)
• Causes: Defective PWB. Defective fuser unit.
• Remedy: Defective PWB. Replace the IH PWB and check for correct operation.
  Defective fuser unit. Replace the fuser unit.

• Code: 6760
• Description: Abnormally AC input overcurrent (IHPWB)
• Causes: Defective PWB.
• Remedy: Replace the IH PWB and check for correct operation.

• Code: 6770
• Description: Abnormally low electric power (IHPWB)
• Causes: Defective connector cable or poor contact in the connector. Defective PWB.
• 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.
  Defective PWB. Replace the IH PWB and check for correct operation.