• Code: L4-17
• Description: Drum motor trouble (BK)
• Causes: Drum motor trouble Connection trouble of the connector and the harness between the PCU PWB and the drum motor. PCU PWB trouble
• Remedy: Check the operation of the drum motor by SIM25-01. Check the connection of the harness and the connector between the PCU PWB and the drum motor. Replace the PCU PWB and the drum motor.

• Code: L4-18
• Description: Drum motor trouble (CL)
• Causes: Drum motor trouble Connection trouble of the connector and the harness between the PCU PWB and the drum motor. PCU PWB trouble
• Remedy: Check the operation of the drum motor by SIM25-01. Check the connection of the harness and the connector between the PCU PWB and the drum motor. Replace the PCU PWB and the drum motor.

• Code: L4-32
• Description: Power source cooling fan trouble
• Causes: Power cooling fan trouble. PCU PWB trouble. Connection trouble of the connector and the harness.
• Remedy: Use SIM6-2 to check that the fan is actually rotating. Replace the power cooling fan. Replace the PCU PWB. Check connection of the connectors and the harness.

• Code: L4-35
• Description: Fusing cooling fan R trouble
• Causes: Fusing cooling fan trouble. PCU PWB trouble. Connection trouble of the connector and the harness.
• Remedy: Use SIM6-2 to check that the fan is actually rotating. Replace the fusing cooling fan. Replace the PCU PWB. Check connection of the connector and the harness.

• Code: L4-43
• Description: Paper exit cooling fan R trouble
• Causes: Fan trouble. PCU PWB trouble. Connection trouble of the connector and the harness.
• Remedy: Check that the fan is rotating after turning ON the power. Replace the fan. Replace the PCU PWB. Check the connector and the harness. Use SIM6-2 to check that the fan is actually rotating.

• Code: L4-50
• Description: Process fan 1 trouble
• Causes: Process fan trouble. PCU PWB trouble. Connection trouble of the connector and the harness.
• Remedy: Check that the fan is rotating after turning ON the power. Replace the process fan. Replace the PCU PWB. Check connection of the connector and the harness.

• Code: L4-51
• Description: Process fan 2 trouble
• Causes: Process fan trouble. PCU PWB trouble. Connection trouble of the connector and the harness.
• Remedy: Check that the fan is rotating after turning ON the power. Replace the process fan. Replace the PCU PWB. Check the connector and the harness.

• Code: L4-71
• Description: Process fan 2 trouble
• Causes: PCU PWB trouble.
• Remedy: Replace the PCU PWB.