• Code: C5303
• Description: Cleaning lamp M error
• Causes: Poor contact in the connector terminals.
  Defective cleaning lamp M.
  Defective PWB.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC7 on the sub front PWB and the connector of the drum unit M, and the continuity across the connector terminals. Repair or replace if necessary.
  Defective cleaning lamp M. Replace the drum unit M.
  Defective PWB. Replace the sub front PWB or engine PWB and check for correct operation.

• Code: C5304
• Description: Cleaning lamp Y error
• Causes: Poor contact in the connector terminals.
  Defective cleaning lamp Y.
  Defective PWB.
• Remedy: Poor contact in the connector terminals. Check the connection of connector YC3 on the sub front PWB and the connector of the drum unit Y, and the continuity across the connector terminals. Repair or replace if necessary.
  Defective cleaning lamp Y. Replace the drum unit Y.
  Defective PWB. Replace the sub front PWB or engine PWB and check for correct operation.

• Code: C6000
• Description: Fuser heater 1 break Fuser thermistor 1 detects a temperature lower than the Ready indication temperature for 90 s during warming up. Fuser thermistor 1 deduced less than 130 C/266F for 5 s during stand-by. Fuser thermistor 1 does not reach 75C/ 167F even after 30 s during warming up.
• Causes: Defective fuser heater 1.
  Defective fuser thermostat 1.
  Installation defectiveness on fuser thermistor 1.
  Defective PWB.
• Remedy: Defective fuser heater 1. Check for continuity across each heater. If none, replace the fuser unit.
  Defective fuser thermostat 1. Check for continuity across thermostat. If none, remove the cause and replace the fuser unit.
  Installation defectiveness on fuser thermistor 1. Measure the resistance. If it is ∞, replace the fuser unit.
  Defective PWB. Replace the power source PWB or engine PWB and check for correct operation.

• Code: C6010
• Description: Abnormally high fuser thermistor temperature
  The fuser Abnormally high signal is detected for 60 s or more.
• Causes: Defective PWB.
• Remedy: Replace the power source PWB or engine PWB and check for correct operation.

• Code: C6020
• Description: Abnormally high fuser thermistor 1 temperature The fuser temperature exceeds 240 C/464 F for 1 s.
• Causes: Installation defectiveness on fuser thermistor 1
  Defective PWB
• Remedy: Installation defectiveness on fuser thermistor 1. Measure the resistance. If it is ∞, replace the fuser unit.
  Defective PWB. Replace the power source PWB or engine PWB and check for correct operation.

• Code: C6030
• Description: Fuser thermistor 1 break error During warming up, fuser thermistor 1 does not detect temperature rise of 1 C/1.8F for 10 s. When the difference of temperature of fuser thermistor 1 and 2 becomes 100C/212F or more.
• Causes: Defective fuser heater 1.
  Installation defectiveness on fuser thermistor 1.
  Defective PWB.
• Remedy: Defective fuser heater 1. Check for continuity across each heater. If none, replace the fuser unit.
  Installation defectiveness on fuser thermistor 1. Measure the resistance. If it is ∞, replace the fuser unit.
  Defective PWB. Replace the power source PWB or engine PWB and check for correct operation.

• Code: C6040
• Description: Fuser heater error
  Fuser thermistor 1 detects temperature change of 20C/36F or more for 160 ms 100 times or more since the power is turned on.
• Causes: Defective fuser heater 1.
  Installation defectiveness on fuser thermistor 1.
  Defective PWB
• Remedy: Defective fuser heater 1. Check for continuity across each heater. If none, replace the fuser unit.
  Installation defectiveness on fuser thermistor 1. Measure the resistance. If it is ∞, replace the fuser unit.
  Defective PWB. Replace the power source PWB or engine PWB and check for correct operation.

• Code: C6050
• Description: Abnormally low fuser thermistor 1 temperature
  During printing, the temperature at the heat roller lower than 100C/212F is detected continuously for 1 s.
• Causes: Defective fuser heater 1.
  Defective PWB
• Remedy: Defective fuser heater 1. Replace the fuser unit.
  Defective PWB. Replace the power source PWB or engine PWB and check for correct operation.