• Code: 390
• Description: Development Bias output error
  The high voltage supply board (C/B) monitors the circuit and detects abnormal conditions such as a voltage leak or no output condition. If this happens, the high voltage supply board sends an error signal (High to Low at CN204A18) to the BCU. The BCU monitors this signal every 2 ms and generates this SC code when the error condition occurs 250 consecutive times.
• Causes: • Loose connection • Defective power pack C/B output • Damaged cable • Defective development unit • Defective BCU

• Code: 391
• Description: Charge AC output error
  391-01: K 391-02: Y 391-03: M 391-04: C The high voltage supply board sends the feedback signal (CN228-2 to 5; MCYK). The BCU monitors these feedback signals every 8 ms. If the average of the sampled data is not within the control target 20 consecutive times, this SC code is generated.
• Causes: • Power pack disconnected • Charge receptacle or terminal • Defective PCU bias input terminal • Incorrect power pack B/C output • Damaged cable • Defective BCU • PCU not found

• Code: 393
• Description: TD sensor error during warming up
  393-001: K 393-002: Y 393-003: C 393-004: M The development-unit drive starts. TD sensor signal is 0.78 V or less.
• Causes: • Loose cable connection • Positioning plate out of place • Defective TD sensor • Development unit not found

• Code: 440
• Description: Drum motor error
  440-001: Black 440-002: Color No drum gear position sensor signal is detected within 0.7 second (185 mm/s), 1.0 second (125 mm/s), or 2.0 seconds (62.5 mm/s).
• Causes: • Defective PCU • Defective drum motor • Defective drum gear position sensor

• Code: 460-001
• Description: Thermistor 1 error (open circuit)
  When the temperature detected by thermistor 1, which is at the left (fusing unit) side of the laser optics unit, is less than -30°C for 10 seconds consecutively, the BCU determines that the circuit is opened and displays this SC code
• Causes: • Thermistor 1 defective • Cable connection error • BCU defect

• Code: 460-002
• Description: Thermistor 1 error (short circuit)
  When the temperature detected by the thermistor 1, which is at the left (fusing unit) side of the laser optics unit, is higher than 70°C for 10 seconds consecutively, the BCU determines that the circuit is shorted and displays this SC code
• Causes: • Thermistor 1 defective • Cable connection error • BCU defect

• Code: 461-001
• Description: Thermistor 2 error (open circuit)
  When the temperature detected by the thermistor 2, which is at the right (paper feed section) side of the laser optics unit, is less than -30°C for 10 seconds consecutively, the BCU determines that the circuit is opened and displays this SC code.
• Causes: • Thermistor 2 defective • Cable connection error • BCU defect

• Code: 461-002
• Description: Thermistor 2 error (short circuit)
  When the temperature detected by the thermistor 2, which is at the right (paper feed section) side of the laser optics unit, is higher than 70°C for 10 seconds consecutively, the BCU determines that the circuit is shorted and displays this SC code
• Causes: • Thermistor 2 defective • Cable connection error • BCU defect