• Code: C0240
• Description: Printer board communication problem • There is no reply after 20 retries at communication.
• Causes: Poor contact in the connector terminals. Defective main PCB or printer board.
• Remedy: Check the connection of connector YC43 on the main PCB and the connector on the printer board. Repair or replace if necessary. Replace the main PCB or printer board and check for correct operation.

• Code: C0250
• Description: Scanner network board communication problem • There is no reply after 20 retries at communication.
• Causes: Poor contact in the connector terminals. Defective main PCB or scanner network board.
• Remedy: Check the connection of connector YC46 on the main PCB and the connector on the memory PCB. Repair or replace if necessary. Replace the main PCB or scanner network board and check for correct operation.

• Code: C0280
• Description: Fax control PCB communication problem • There is no reply after 20 retries at communication.
• Causes: Poor contact in the connector terminals. Defective main PCB or fax control PCB.
• Remedy: Check the connection of connector YC44 on the main PCB and the connector on the memory PCB. Repair or replace if necessary. Replace the main PCB or fax control PCB and check for correct operation.

• Code: C0320
• Description: Energy save communication problem • Communication errors from the communication microcomputer on the main PCB. No communication: there is no reply after 5 retries. Abnormal communication: a communication error (parity or checksum error) is detected five times in succession.
• Causes: Defective main PCB.
• Remedy: Replace the main PCB and check for correct operation.

• Code: C0420
• Description: Large paper deck/paper feeder communication problem • Communication errors from the communication microcomputer on the main PCB. No communication: there is no reply after 5 retries. Abnormal communication: a communication error (parity or checksum error) is detected five times in succession.
• Causes: Poor contact in the connector terminals. Defective main PCB. Defective deck main PCB/desk main PCB.
• Remedy: Check the connection of connectors CN3 on the main PCB and the connector on the deck main PCB/desk main PCB, and the continuity across the connector terminals. Repair or replace if necessary. Replace the main PCB and check for correct operation. Replace the deck main PCB/desk main PCB and check for correct operation.

• Code: C0440
• Description: Finisher communication problem • Communication errors from the communication microcomputer on the main PCB. No communication: there is no reply after 5 retries. Abnormal communication: a communication error (parity or checksum error) is detected five times in succession.
• Causes: Poor contact in the connector terminals. Defective main PCB. Defective finisher main PCB.
• Remedy: Check the connection of connectors YC4, YC5 on the main PCB and CN2 on the finisher main PCB, and the continuity across the connector terminals. Repair or replace if necessary. Replace the main PCB and check for correct operation. Replace the finisher main PCB and check for correct operation.

• Code: C0450
• Description: Mailbox communication problem • Communication errors from the communication microcomputer on the main PCB. No communication: there is no reply after 5 retries. Abnormal communication: a communication error (parity or checksum error) is detected five times in succession.
• Causes: Poor contact in the connector terminals. Defective main PCB. Defective mailbox main PCB.
• Remedy: Check the connection of connectors YC3 on the main PCB and CN1 on the mailbox main PCB, and the continuity across the connector terminals. Repair or replace if necessary. Replace the main PCB and check for correct operation. Replace the mailbox main PCB and check for correct operation.

• Code: C0470
• Description: Switchback unit communication problem • Communication errors from the communication microcomputer on the main PCB. No communication: there is no reply after 5 retries. Abnormal communication: a communication error (parity or checksum error) is detected five times in succession.
• Causes: Poor contact in the connector terminals. Defective main PCB. Defective switchback unit main PCB.
• Remedy: Check the connection of connectors YC3 on the main PCB and the continuity across the connector terminals. Repair or replace if necessary. Replace the main PCB and check for correct operation. Replace the switchback unit main PCB and check for correct operation.