• Code: F2-47
• Description: Room temperature thermistor trouble
  Room temperature thermistor open or short
• Causes: Room temperature thermistor trouble, room temperature thermistor harness connection trouble, PCU PWB trouble.
• Remedy: Check connection of the room temperature harness / connector. Check the PCU PWB.

• Code: F2-58
• Description: Process humidity sensor trouble
• Causes: Temperature/humidity sensor trouble. Process humidity sensor harness and connector connection trouble PCU PWB trouble.
• Remedy: Replace the temperature/humidity sensor. Check connection of the temperature/humidity sensor harness and the connector. Replace the PCU PWB.

• Code: F2-59
• Description: Room temperature/humidity thermistor trouble
  Room temperature humidity sensor open
• Causes: Room temperature humidity sensor trouble, room temperature humidity sensor harness connection trouble, PCU PWB trouble.
• Remedy: Check connection of the room temperature humidity sensor harness/connector. Check the PCU PWB.

• Code: F2-64
• Description: Toner supply operation trouble (K)
• Causes: Toner motor trouble. Toner density sensor trouble. Connector/harness trouble. PCU PWB trouble. Toner cartridge trouble. Developing unit trouble. Toner hopper section trouble
• Remedy: Replace the toner motor. Replace the toner density sensor. Connector and harness check. Replace the PCU PWB. Replace the toner cartridge. Replace the developing unit. Check the toner hopper section.

• Code: F2-70
• Description: Improper toner cartridge detection (K)
• Causes: An improper toner cartridge is inserted. (The main unit detects a toner cartridge of a different specification.) Toner cartridge trouble. PCU PWB trouble.
• Remedy: Replace the toner cartridge. Replace the PCU PWB.

• Code: F2-74
• Description: Toner cartridge CRUM error (K)
• Causes: Toner cartridge (CRUM) trouble. PCU PWB trouble. Connector and harness trouble between PCU PWB and toner cartridge
• Remedy: Replace the toner cartridge. Replace the PCU PWB. Check the connector and the harness between the PCU PWB and the toner cartridge.

• Code: F2-78
• Description: Image density sensor adjustment trouble
  Before registration, the transfer belt surface is scanned by the image density sensor to adjust the sensor gain so that the output is maintained at a constant level. When, however, the sensor gain is changed, the output level does not fall within the specified range.
• Causes: Image density sensor trouble. Connection trouble of the harness between the PCU PWB and the image density sensor. Dirt on the image density sensor, transfer belt cleaning trouble Calibration plate solenoid operation trouble
• Remedy: Check the sensor and the harness Check the operation of the calibration plate solenoid, and check the transfer belt surface conditions. If the trouble is not removed, perform the following procedures depending on the check results. Replace the registration image sensor. Replace the transfer belt. Replace the calibration plate solenoid. Replace the PCU PWB.

• Code: F2-91
• Description: High density process control high voltage error (K)
  When executing the high density process control in the toner cartridge-less production process, the developing bias exceeds 500V.
• Causes: • Image density sensor trouble, harness connection trouble between the PCU PWB and the image density sensor, dirt on the image density sensor, transfer belt cleaning trouble • Developing tank abnormality
• Remedy: • Use SIM44-02 to execute the gain adjustment of the process control sensor. When "Error" is displayed, it may be considered as breakdown. Check the sensor and the harness. When the adjustment is normally completed, check the drum surface and the belt surface. • Replace the developing tank.