• Code: F2-44
• Description: Black exclusive image density sensor trouble (Transfer belt surface reflection ratio abnormality)
  The transfer belt surface is scanned by the image density sensor before starting the process control, and adjust the sensor gain so that the output is kept at a certain level. However, the output is not within the specified range though the senor gain is adjusted.
• Causes: Image density sensor trouble, harness connection trouble between PCU PWB and the image density sensor, image density sensor dirt, transfer belt cleaning trouble, calibration plate solenoid operation trouble
• Remedy: Use SIM44-2 to execute the process control sensor gain adjustment. If "ERROR" is displayed, check the sensor, the harness, the calibration plate solenoid operation for any trouble. If the adjustment is completed, check the transfer belt surface state.

• Code: F2-45
• Description: Color exclusive image density sensor trouble (Calibration plate surface reflection ratio abnormality)
  The calibration plate surface is scanned by the image density sensor before starting the process control, and adjust the sensor gain so that the output is kept at a certain level. However, the output is not within the certain level though the senor gain is adjusted.
• Causes: Image density sensor trouble, harness connection trouble between PCU PWB and the image density sensor, image density sensor dirt, calibration plate dirt, calibration plate solenoid operation trouble
• Remedy: Use SIM44-2 to execute the process control gain adjustment. If "ERROR" is displayed, check the sensor and the harness. If the adjustment is completed, check the calibration plate solenoid operation.

• Code: F2-49
• Description: LSU thermistor trouble
  The detection temperature is out of the range of 5°C to 55°C.
• Causes: LSU thermistor harness connection trouble LSU thermistor trouble, PCU PWB trouble
• Remedy: Check the PCU PWB. If the trouble cannot be removed, replace the LSU thermistor or the PCU PWB.

• Code: F2-50
• Description: K phase sensor sensing trouble
  Detection is made by interruption of light in the sensor section of the projection rib on the drum drive gear to control the BK drum phase. The detection signal cannot be acquired and phase control cannot be made.
• Causes: Sensor connector connection trouble Dirt on the sensor light emitting section, or installation trouble Drum drive gear upper rib breakage, sensor trouble
• Remedy: Case 1 Cause Sensor connector connection trouble Check and remedy Check the sensor connector connection. Case 2 Cause Dirt on the sensor light emitting section, or installation trouble Check and remedy Check for dirt on the sensor or check the installation state. Case 3 Cause Drum drive gear upper rib breakage, sensor trouble Check and remedy If there is no trouble in the rib, replace the sensor. (Use SIM30-1 "DHPD_K" to check interruption or transmission of light.)

• Code: F2-51
• Description: CL phase sensor sensing trouble
  Detection is made by interruption of light in the sensor section of the projection rib on the drum drive gear to control the phases of all the color drums. The detection signal cannot be acquired and phase control cannot be made.
• Causes: Sensor connector connection trouble Dirt on the sensor light emitting section, or installation trouble Drum drive gear upper rib breakage, sensor trouble
• Remedy: Case 1 Cause Sensor connector connection trouble Check and remedy Check the sensor connector connection. Case 2 Cause Dirt on the sensor light emitting section, or installation trouble Check and remedy Check for dirt on the sensor or check the installation state. Case 3 Cause Drum drive gear upper rib breakage, sensor trouble Check and remedy If there is no trouble in the rib, replace the sensor. (Use SIM30-1 "DHPD_CL" to check interruption or transmission of light.)

• Code: F2-58
• Description: Process humidity sensor trouble
  Process humidity sensor open
• Causes: Process humidity sensor harness connection trouble Process humidity sensor trouble PCU PWB trouble
• Remedy: Case 1 Cause Process humidity sensor harness connection trouble Check and remedy Check the harness and connector connection of the process humidity sensor. Case 2 Cause Process humidity sensor trouble Check and remedy Check the process humidity sensor. Case 3 Cause PCU PWB trouble Check and remedy Check the PCU PWB.

• Code: F2-64
• Description: Toner supply abnormality (BLACK)
  Toner end with the remaining quantity of 50% or more. The toner supply time exceeds 3 times as much as the specified time.
• Causes: Toner motor section connector harness trouble Toner motor and toner density sensor trouble
• Remedy: Case 1 Cause Toner motor section connector harness trouble Check and remedy Check the connector connection of the toner motor section. Check the connector harness (TM) connection to the main PWB. Case 2 Cause Toner motor and toner density sensor trouble Check and remedy Check the toner density sensor output. (SIM25-1) Check that the toner transport pipe is not clogged between the toner cartridge and the developing unit. Replace the toner cartridge (CRUM) if necessary. If replacement of the toner cartridge (CRUM) does not clear the trouble, check the developing unit.

• Code: F2-65
• Description: Toner supply abnormality (CYAN)
  Toner end with the remaining quantity of 50% or more. The toner supply time exceeds 3 times as much as the specified time.
• Causes: Toner motor section connector harness trouble Toner motor and toner density sensor trouble
• Remedy: Case 1 Cause Toner motor section connector harness trouble Check and remedy Check the connector connection of the toner motor section. Check the connector harness (TM) connection to the main PWB. Case 2 Cause Toner motor and toner density sensor trouble Check and remedy Check the toner density sensor output. (SIM25-1) Check that the toner transport pipe is not clogged between the toner cartridge and the developing unit. Replace the toner cartridge (CRUM) if necessary. If replacement of the toner cartridge (CRUM) does not clear the trouble, check the developing unit.