• Code: C4010
• Description: Polygon motor steady-state problem • The polygon motor rotation is not stable for 5 s after the polygon motor rotation has been stabilized.
• Causes: Poor contact in the polygon motor connector terminals. Defective polygon motor. Defective engine PWB.
• Remedy: Poor contact in the polygon motor connector terminals. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Defective polygon motor. Replace the laser scanner unit. Defective engine PWB. Check if 24 V DC is supplied to YC17-1 on the engine PWB. If not, replace the engine PWB.

• Code: C4100
• Description: BD initialization (A) problem • When power is turned on, only laser A is output and ASIC of main PWB detects a BD error for 2000 ms.
• Causes: Defective laser scanner unit. Defective main PWB. Poor contact in connector terminals.
• Remedy: Defective laser scanner unit. Replace the laser scanner unit. Defective main PWB. Replace the main PWB and check for correct operation. Poor contact in connector terminals. Check the connection of connector YC8 on the main PWB. Repair or replace if necessary.

• Code: C4110
• Description: BD initialization (B) problem • When power is turned on, only laser B is output and ASIC of main PWB detects a BD error for 2000 ms.
• Causes: Defective laser scanner unit. Defective main PWB. Poor contact in connector terminals.
• Remedy: Defective laser scanner unit. Replace the laser scanner unit. Defective main PWB. Replace the main PWB and check for correct operation. Poor contact in connector terminals. Check the connection of connector YC8 on the main PWB and the continuity across the connector terminals. Repair or replace if necessary.

• Code: C4120
• Description: BD initialization (C) problem • When power is turned on, only laser C is output and ASIC of main PWB detects a BD error for 2000 ms.
• Causes: Defective laser scanner unit. Defective main PWB. Poor contact in connector terminals.
• Remedy: Defective laser scanner unit. Replace the laser scanner unit. Defective main PWB. Replace the main PWB and check for correct operation. Poor contact in connector terminals. Check the connection of connector YC8 on the main PWB and the continuity across the connector terminals. Repair or replace if necessary.

• Code: C4200
• Description: BD steady-state problem • ASIC of the main PWB detects a BD error A for 4000 ms after the polygon motor rotation has been stabilized.
• Causes: Defective laser diode. Defective polygon motor. Defective main PWB. Poor contact in connector terminals.
• Remedy: Defective laser diode. Replace the laser scanner unit. Defective polygon motor. Replace the laser scanner unit. Defective main PWB. Replace the main PWB and check for correct operation. Poor contact in connector terminals. Check the connection of connector YC8 on the main PWB and the continuity across the connector terminals. Repair or replace if necessary.

• Code: C5100
• Description: Main high-voltage error • While the main high-voltage output remote signal is on, an alarm signal is detected continuously for 400 ms.
• Causes: Defective high voltage PWB. Leak of main high-voltage. Poor contact in connector terminals.
• Remedy: Defective high voltage PWB. Replace the high voltage PWB and check for correct operation. Leak of main highvoltage. Check the main charger unit and replace if necessary. Poor contact in connector terminals. Check the connection of connector YC7 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary.

• Code: C5500
• Description: Drum surface potential sensor problem 1 • The sensor output is 0.5 V or less when MC REM signal is turned on.
• Causes: Poor contact in the drum surface potential sensor connector terminals. Defective drum surface potential sensor. Defective high voltage PWB. Defective engine PWB.
• Remedy: Poor contact in the drum surface potential sensor connector terminals. Check the connection of connector YC5 on the engine PWB. Reinsert the connector. Also check for continuity within the connector cable. If none, repair or replace the cable. Defective drum surface potential sensor. Replace the drum surface potential sensor. Defective high voltage PWB. Replace the high voltage PWB and check for correct operation. Defective engine PWB. Replace the engine PWB and check for correct operation.

• Code: C5510
• Description: Drum surface potential sensor problem 2 • The sensor output is 4.5 V or more when the MC REM signal is turned on.
• Causes: Defective drum surface potential sensor. Defective high voltage PWB. Poor contact in the drum surface potential sensor.
• Remedy: Defective drum surface potential sensor. Replace the drum surface potential sensor. Defective high voltage PWB. Replace the high voltage PWB and check for correct operation. Poor contact in the drum surface potential sensor. Check the connection of connector YC5 on the engine PWB. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable.