• Code: 6410
• Description: Fuser unit connector insertion problem
  • Absence of the fuser unit is detected.
• Causes: Fuser unit connector inserted incorrectly. Defective fuser unit connector.
• Remedy: Reinsert the fuser unit connector if necessary. Replace the fuser unit.

• Code: 6420
• Description: Fuser unit fuse cut problem
  • When you try to cut the fuser fuse, the fuse is not cut even after 3 s elapse.
• Causes: Poor contact in the connector terminals. Fuser unit connector inserted incorrectly.
• Remedy: Check the connection of connector YC10 on the engine controller PWB and the continuity across the connector terminals. Repair or replace if necessary. Reinsert the fuser unit connector if necessary.

• Code: 7300
• Description: Toner sensor problem
  • While the toner container sensor is on, the toner sensor in the developing unit does not turn on after the toner sensor turns off and toner is replenished from the toner container.
• Causes: Defective toner sensor. Poor contact in the toner sensor connector terminals. Defective toner container sensor. Defective toner container.
• Remedy: Replace the toner sensor. Reinsert the connector. Also check for continuity within the connector cable. If none, remedy or replace the cable. Replace the toner container sensor. Replace the toner container.

• Code: 7400
• Description: Developing unit connector insertion problem
  • Absence of the developing unit is detected.
• Causes: Developing unit connector inserted incorrectly. Defective developing unit connector.
• Remedy: Reinsert the developing unit connector if necessary. Replace the developing unit.

• Code: 7410
• Description: Drum unit connector insertion problem
  • Absence of the drum unit is detected.
• Causes: Drum unit connector inserted incorrectly. Defective drum unit connector.
• Remedy: Reinsert the drum unit connector if necessary. Replace the drum unit.

• Code: 7450
• Description: Developing unit fuse cut problem
  • The developer unit fuse cannot be cut.it co
• Causes: Developing unit connector inserted incorrectly. Defective developing unit connector.
• Remedy: Reinsert the developing unit connector if necessary. Replace the developing unit.

• Code: 7800
• Description: Broken external temperature thermistor wire
  • The input voltage is above 4.5 V.
• Causes: Poor contact in the humidity sensor board 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 humidity sensor board.

• Code: 7810
• Description: Short-circuited external temperature thermistor • The input voltage is below 1.0 V.
• Causes: Poor contact in the humidity sensor board 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 humidity sensor board.