• Code: 0503
• Description: Thermistor resistance failure
  - The difference between the temperature detected by thermistor/1 and that detected by thermistor/2 exceeds a predetermined value.
• Causes: Fuser unit Print control board (PRCB) DC power supply (DCPU)
• Remedy: 1 Check the fuser unit for correct installation (whether it is secured in position). 2 Check the fuser unit, DCPU, and PRCB for proper connection and correct as necessary. 3 Change fuser unit. 4 Change PRCB. 5 Change DCPU.

• Code: 0510
• Description: Abnormally low heating roller temperature
  - The temperature detected by the thermistor /1 remains lower than the specified value for a given period of time or longer.
• Causes: Fuser unit Print control board (PRCB) DC power supply (DCPU)
• Remedy: 1 Check the fuser unit for correct installation (whether it is secured in position). 2 Check the fuser unit, DCPU, and PRCB for proper connection and correct as necessary. 3 Change fuser unit. 4 Change PRCB. 5 Change DCPU.

• Code: 0520
• Description: Abnormally high heating roller temperature
  - The temperature detected by the thermistor /1 remains higher than the specified value for a given period of time or longer
  - The heater lamp remains ON for a given period of time or longer
• Causes: Fuser unit Print control board (PRCB) DC power supply (DCPU)
• Remedy: 1 Check the fuser unit for correct installation (whether it is secured in position). 2 Check the fuser unit, DCPU, and PRCB for proper connection and correct as necessary. 3 Change fuser unit. 4 Change PRCB. 5 Change DCPU.

• Code: 0650
• Description: Scanner home sensor abnormalities
  
• Causes: - A low motor lock signal is not detected even after the lapse of a predetermined period of time after the polygon motor has been started.
  - The motor lock signal remains HIGH for a predetermined consecutive period of time while the polygon motor remains energized.
• Remedy:

• Code: 0F50
• Description: OHP sensor malfunction
  - It is determined that the OHP sensor is faulty through a check made at the end of the predrive.
• Causes: OHP sensor (PS7) Print control board (PRCB)
• Remedy: 1 Check the PRCB connector for proper connection and correct as necessary. 2 PS7 sensor check PRCB PJ15-5 (ON) C to D-6 3 Change PRCB.

• Code: 0F52
• Description: Toner level sensor /Y malfunction
  - An error occurs on the toner level sensor board (TLSB).
• Causes: Toner level sensor board (TLSB) Print control board (PRCB)
• Remedy: 1 Check the cable and connector for proper connection and correct as necessary. 2 Change TLSB. 3 Change PRCB.

• Code: 0F53
• Description: Toner level sensor / M malfunction
  - An error occurs on the toner level sensor board (TLSB).
• Causes: Toner level sensor board (TLSB) Print control board (PRCB)
• Remedy: 1 Check the cable and connector for proper connection and correct as necessary. 2 Change TLSB. 3 Change PRCB.

• Code: 0F54
• Description: Toner level sensor / C malfunction
  - An error occurs on the toner level sensor board (TLSB).
• Causes: Toner level sensor board (TLSB) Print control board (PRCB)
• Remedy: 1 Check the cable and connector for proper connection and correct as necessary. 2 Change TLSB. 3 Change PRCB.