• Code: 71
• Description: Polygon motor failure
  (Cannot detect the period signal of the polygon mirror motor.)
• Causes:
• Remedy: 1 Laser unit harness connection failure Check the two harness connections of the laser unit and reconnect them. 2 Laser unit failure Replace the laser unit. 3 Main PCB failure Replace the main PCB ASSY.

• Code: 72
• Description: BD beam detecting sensor malfunction
• Causes: Laser unit harness connection failure. Laser unit failure. Main PCB failure
• Remedy: 1 Laser unit harness connection failure Check the two harness connections of the laser unit and reconnect them. 2 Laser unit failure Replace the laser unit. 3 Main PCB failure Replace the main PCB ASSY.

• Code: 75
• Description: Machine cooling down inside
• Causes: The temperature inside the machine is too high. Both ends of the heat roller are at different temperatures. The paper media is replaced with different Paper size media.
• Remedy: • After having passed for a while with having turned the power supply on.

• Code: 76
• Description: Fuser unit failure
  (The center thermistor detects rapidly rising temperature.)
• Causes:
• Remedy: 1 Fuser unit harness connection failure Check the harness connection of the fuser unit and reconnect it. 2 Fuser unit failure Replace the fuser unit.

• Code: 77
• Description: Fuser unit failure
  Fuser error code failure (The error history of the fuser unit is deleted.)
• Causes:
• Remedy: 1 Fuser unit failure Replace the fuser unit. 2 Main PCB failure Replace the main PCB ASSY.

• Code: 78
• Description: Fuser unit failure
  (The temperature sensor of the fuser unit is broken.)
• Causes:
• Remedy: 1 Fuser unit failure Replace the fuser unit. 2 Main PCB failure Replace the main PCB ASSY.

• Code: 79
• Description: No detection of the internal temperature thermistor
• Causes: Harness connection failure of internal temperature thermistor Internal temperature thermistor failure Main PCB failure
• Remedy: 1 Harness connection failure of internal temperature thermistor Check the harness connection of the internal temperature thermistor, and reconnect it. 2 Internal temperature thermistor failure Replace the internal temperature thermistor. 3 Main PCB failure Replace the main PCB ASSY.

• Code: 7A
• Description: No detection of main motor lock signal
• Causes: Main motor failure Main PCB failure
• Remedy: 1 Main motor failure Replace the main motor ASSY. 2 Main PCB failure Replace the main PCB ASSY.