• Code: C-3901
• Description: Inferior contact of the thermistor /1 (TH1)
  - While in the warm-up condition, when the thermistor /2 (TH2) detection temperature gets to the Ready temperature before the TH1 detection temperature, the TH1 detection temperature does not get to the Ready temperature a specified period of time after the TH2 detection temperature got to the Ready temperature.
• Causes: Thermistor /1 (TH1) Printer control board (PRCB)

• Code: C-3902
• Description: Inferior contact of the thermistor /2 (TH2)
  - While in the warm-up condition, when the thermistor /1 (TH1) detection temperature gets to the Ready temperature before the TH2 detection temperature, the TH2 detection temperature does not get to the Ready temperature a specified period of time after the TH1 detection temperature got to the Ready temperature
• Causes: Thermistor /2 (TH2) Printer control board (PRCB)

• Code: C-3903
• Description: Thermistor /1 (TH1) open abnormality (sub CPU detection)
  - In the sub CPU, the TH1 detection temperature detects a temperature between -8 and 20 °C for more than a specified period of time.
• Causes: Thermistor /1 (TH1) Printer control board (PRCB)

• Code: C-3904
• Description: Thermistor /2 (TH2) open abnormality (sub CPU detection)
  - In the sub CPU, the TH2 detection temperature detects a temperature between -8 and 20 °C for more than a specified period of time.
• Causes: Thermistor /2 (TH2) Printer control board (PRCB)

• Code: C-4001
• Description: Index board (INDEXB) contact abnormality.
• Causes: Index board (INDEXB) Overall control board (OACB)

• Code: C-4101
• Description: Polygon motor (M5) speed abnormality.
  - When M5 is ON, an error signal is detected 3 times in succession within a specified period of time.
• Causes: Polygon motor (M5) Printer control board (PRCB)

• Code: C-4401
• Description: Laser drive board (LDB) abnormality.
  - When an overcurrent flows for laser output.
• Causes: Laser drive board (LDB) Overall control board (OACB)

• Code: C-4701
• Description: Laser index abnormality.
  - When the cycle of the index is different from an expected value.
• Causes: Index board (INDEXB) Overall control board (OACB)