• Code: L4-04
• Description: Toner hopper/Developing motor trouble
  The motor lock signal is detected during rotation of the toner hopper/developing motor
• Causes: Toner hopper/developing motor trouble. Harness connection trouble between the PCU PWB and the toner hopper/developing motor. Control circuit trouble.
• Remedy: Check the toner hopper/developing motor operation with Sim. 25-1. Check connection of the connector and the harness between the PCU PWB and the toner hopper/ developing motor.

• Code: L4-14
• Description: Toner cartridge motor lock trouble
  Though the toner cartridge motor is rotated for a certain time, the toner cartridge motor rotation sensor count value does not exceed the threshold value
• Causes: Toner cartridge motor trouble. Toner cartridge motor rotation sensor trouble. Harness connection trouble between the PCU PWB and the toner cartridge motor. Harness trouble between the PCU PWB and the toner cartridge motor rotation sensor. Toner cartridge trouble.
• Remedy: Use Sim. 10-1 to check the operation of the toner cartridge motor. Use Sim. 10-3 to check the operation of the toner cartridge motor rotation sensor. Check the harness and the connector between the PCU PWB and the toner cartridge motor. Check the harness and the connector between the PCU PWB and the toner cartridge motor rotation sensor. Replace the toner cartridge.

• Code: L4-17
• Description: Drum motor lock trouble (K)
  The motor lock signal is detected during rotation of the drum motor (K).
• Causes: Drum motor trouble Harness connection trouble between the PCU PWB and the drum motor Control circuit trouble
• Remedy: Use SIM25-01 to check the operation of the drum motor. Check the harness and the connector between the PCU PWB and the developing motor. Replace the PCU PWB. Replace the drum motor.

• Code: L4-27
• Description: Decurler motor lock trouble
  The lock signal is detected during rotation of the decurler motor.
• Causes: Decurler motor trouble. Harness connection trouble between the PCU PWB and the decurler motor. Control circuit trouble.
• Remedy: Use SIM06-01 to check the operation of the decurler motor. Replace the decurler motor. Check connection of the decurler motor harness and the connector. Replace the PCU PWB.

• Code: L4-28
• Description: Sub power source cooling fan motor
  The motor lock signal is detected during rotation of the sub power cooling fan motor.
• Causes: Fan motor trouble, Mother PWB trouble, fan motor/Mother PWB harness connection trouble, control circuit trouble
• Remedy: Use SIM06-02 to check the operation of the fan motor. Check the mother PWB, and the harness and the connector between the fan motor and the Mother PWB.

• Code: L4-30
• Description: Controller fan motor trouble
  The motor lock signal is detected during rotation of the controller fan motor or the HDD fan motor.
• Causes: Fan motor trouble, Mother PWB trouble, fan motor/Mother PWB harness connection trouble, control circuit trouble
• Remedy: Use SIM06-02 to check the operation of the fan motor. Check the Mother PWB, and the harness and the connector between the fan motor and the Mother PWB.

• Code: L4-31
• Description: Machine heat-exhaust fan trouble
  The lock signal is detected during rotation of the machine heat-exhaust fan.
• Causes: The fan does not rotate because of disconnection of the fan connector or other trouble.
• Remedy: Check the harness and the connector between the PCU PWB and the fan. Use SIM6-2 to check that the fan is actually rotating.

• Code: L4-32
• Description: Power source cooling fan trouble
  The motor lock signal is detected during rotation of the power cooling fans 1 and 2.
• Causes: The fan does not rotate because of disconnection of the ozone exhaust fan or other trouble.
• Remedy: Check the harness and the connector between the PCU PWB and the fan. Use SIM6-2 to check that the fan is actually rotating.