• Code: L4-14
• Description: Toner cartridge motor lock trouble
• 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)
• 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
• 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
• 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
• 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
• 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
• 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.

• Code: L4-34
• Description: Polygon cooling fan trouble
• 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.