• Code: 4000
• Description: Polygon motor synchronization problem
  The polygon motor does not reach the stable speed within 20 s of the START signal turning on.s
• Causes: Poor contact in the connector terminals. Defective polygon motor. Defective engine PWB.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC8 on the engine PWB and laser scanner unit, and the continuity across the connector terminals. Repair or replace if necessary. Defective polygon motor. Replace the laser scanner unit. Defective engine PWB. Replace the engine PWB and check for correct operation.

• Code: 4010
• Description: Polygon motor steady-state problem
  The polygon motor rotation is not stable for 20 s after the polygon motor rotation has been stabilized.
• Causes: Poor contact in the connector terminals. Defective polygon motor. Defective engine PWB.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC8 on the engine PWB and laser scanner unit, and the continuity across the connector terminals. Repair or replace if necessary. Defective polygon motor. Replace the laser scanner unit. Defective engine PWB. Replace the engine PWB and check for correct operation.

• Code: 4200
• Description: BD steady-state problem
  ASIC detects a BD error A for 2 s after the polygon motor rotation has been stabilized.
• Causes: Poor contact in the connector terminals. Defective laser scanner unit. Defective engine PWB.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC8 on the engine PWB and laser scanner unit, and the continuity across the connector terminals. Repair or replace if necessary. Defective laser scanner unit. Replace the laser scanner unit. Defective engine PWB. Replace the engine PWB and check for correct operation.

• Code: 5300
• Description: Broken cleaning lamp wire
  While the cleaning lamp is on, the broken cleaning lamp wire detection signal is detected for 2 s continuously.
• Causes: Defective cleaning lamp. Defective engine PWB.
• Remedy: Defective cleaning lamp. Replace the cleaning lamp. Defective engine PWB. Replace the engine PWB and check for correct operation.

• Code: 6000
• Description: Fuser heater brea
  Fuser thermistor 1 is detected 40°C/ 104°F below with 10 s continuously during warm-up and ready in.
• Causes: Defective fuser heater M or S. Installation defectiveness on fuser thermistor 1. Defective fuser thermostat. Defective PWB.
• Remedy: Defective fuser heater M or S. Replace the fuser heater M or S. Installation defectiveness on fuser thermistor 1. Check the mounting state of the fuser thermistor 1. If any problem is found, repair it. Defective fuser thermostat. Replace the fuser thermostat. Defective PWB. Replace the power source PWB or engine PWB and check for correct operation.

• Code: 6020
• Description: Abnormally high fuser thermistor temperature
  Fuser thermistor 1 or 2 is detected 230°C/446°F or more for 40 ms.
• Causes: Installation defectiveness on fuser thermistor 1 or 2. Defective fuser thermistor 1 or 2. Defective engine PWB.
• Remedy: Installation defectiveness on fuser thermistor 1 or 2. Check the mounting state of the fuser thermistor 1 or 2. If any problem is found, repair it. Defective fuser thermistor 1 or 2. Replace the fuser thermistor 1 or 2. Defective engine PWB. Replace the engine PWB and check for correct operation.

• Code: 6030
• Description: Fuser thermistor break error
  The thermistor break signal is detected continuously for 500 ms.
• Causes: Installation defectiveness on fuser thermistor 1 or 2. Defective fuser thermistor 1 or 2. Defective engine PWB.
• Remedy: Installation defectiveness on fuser thermistor 1 or 2. Check the mounting state of the fuser thermistor 1 or 2. If any problem is found, repair it. Defective fuser thermistor 1 or 2. Replace the fuser thermistor 1 or 2. Defective engine PWB. Replace the engine PWB and check for correct operation.

• Code: 6050
• Description: Abnormally low fuser thermistor 3 temperature
  Fuser thermistor 1 is detected 100°C/ 212°F less than 1 s continuously during copying.
• Causes: Defective fuser heater M or S. Installation defectiveness on fuser thermistor 1. Defective PWB.
• Remedy: Defective fuser heater M or S. Replace the fuser heater M or S. Installation defectiveness on fuser thermistor 1. Check the mounting state of the fuser thermistor 1. If any problem is found, repair it. Defective PWB. Replace the power source PWB or engine PWB and check for correct operation.