• Code: C3200
• Description: Exposure lamp problem
  • In indicator check before starting copying, the average value in scanning of the shading plate with the CCD is 128 or more.
• Causes: Defective scanner PWB. Defective exposure lamp or inverter PWB. Incorrect shading position. Poor contact of the connector terminals.
• Remedy: Replace the scanner PWB and check for correct operation. Replace the exposure lamp or inverter PWB. Adjust the position of the contact glass (shading plate). If the problem still occurs, replace the scanner home position sensor. Check the connection of connector YC7 on the scanner PWB, and the continuity across the connector terminals. Repair or replace if necessary.

• Code: C4000
• Description: Polygon motor synchronization problem
  • The polygon motor does not reach the stable speed within 15 s of the START signal turning on.
• Causes: Poor contact in the polygon motor connector terminals. Defective polygon motor. Defective engine PWB (KP-5238).
• Remedy: Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Replace the LSU. Replace the engine PWB and check for correct operation.

• 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 (KP-5238).
• Remedy: Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Replace the LSU. Replace the engine PWB and check for correct operation.

• Code: C6000
• Description: Broken fusing heater wire
  • In fusing warm-up, the time to reach 50 C/122 F exceeds 13.5 s, the time to reach 100 C/212 F exceeds 10 s, the time to reach the primary stabilization exceeds 10 s or the time to reach the secondary stabilization exceeds 24 s.
• Causes: Poor contact in the thermistor connector terminals. Thermistor installed incorrectly. Thermal cutout triggered. Heater lamp installed incorrectly. Broken heater lamp wire.
• Remedy: Check the connection of connector YC4 on the power supply PWB and the continuity across the connector terminals. Repair or replace if necessary. Check and reinstall if necessary. Check for continuity. If none, replace the thermal cutout. Check and reinstall if necessary. Check for continuity. If none, replace the heater lamp.

• Code: C6020
• Description: Abnormally high fusing unit thermistor temperature
  • The fusing temperature exceeds 230 C/446 F for 40 ms.
• Causes: Shorted thermistor. Broken heater control circuit on the power supply PWB.
• Remedy: Measure the resistance. If it is 0 Ω, replace the thermistor. Replace the power supply PWB and check for correct operation.

• Code: C6050
• Description: Abnormally low fusing unit thermistor temperature
  • The fusing temperature remains below 90C/194F for 1 s.
• Causes: Poor contact in the thermistor connector terminals. Broken thermistor wire. Thermistor installed incorrectly. Thermal cutout triggered. Heater lamp installed incorrectly. Broken heater lamp wire.
• Remedy: Check the connection of connector YC4 on the power supply PWB and the continuity across the connector terminals. Repair or replace if necessary. Measure the resistance. If it is ∞Ω, replace the thermistor. Check and reinstall if necessary. Check for continuity. If none, replace the thermal cutout. Check and reinstall if necessary. Check for continuity. If none, replace the heater lamp.

• Code: C6400
• Description: Zero-crossing signal problem
  • The engine PWB does not detect the zero-crossing signal for the time specified below. At power-on: 3 s Others: 5 s
• Causes: Poor contact in the connector terminals. Defective power supply PWB. Defective engine PWB.
• Remedy: Check the connection of connectors YC7 on the engine PWB and YC2 on the power supply PWB, and the continuity across the connector terminals. Repair or replace if necessary. Check if the zero-crossing signal is output from YC2-11 on the power supply PWB. If not, replace the power supply PWB. Replace the engine PWB if C6400 is detected while YC2-11 on the power supply PWB outputs the zero-crossing signal.

• Code: C7800
• Description: Broken external temperature thermistor
  • The input voltage is 0.5 V or less.
• Causes: Poor contact in the operation PWB connector terminals. Defective external temperature thermistor.
• Remedy: Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Replace the operation PWB and check for correct operation.