• Code: 541
• Description: Fusing thermistor open (center)
  The fusing temperature detected by the thermistor is below 71°C and is not corrected after the main power switch is turned on.
• Causes: • Fusing thermistor defective or out of position
  • Power supply board defective
  • Loose connectors

• Code: 542
• Description: Fusing temperature warm-up error (center)
  The fusing temperature rises less than 7 degrees in 2 seconds, and this continues 5 times consecutively. The fusing temperature is not detected in 25 or 35 seconds.
• Causes: - Fusing thermistor defective or out of position
  - Fusing lamp open
  - Power supply board defective

• Code: 543
• Description: Fusing overheat error (center)
  The fusing temperature is over 230°C for 1 second (detected by the thermistor).
• Causes: - Fusing thermistor defective
  - Power supply board defective

• Code: 544
• Description: Fusing overheat error (center) 2
  The fusing temperature is over 250°C for 1 second (detected by the fusing temperature monitor circuit).
• Causes: - Fusing thermistor defective
  - Power supply board defective

• Code: 545
• Description: Fusing lamp overheat error (center)
  After the fusing temperature reaches the target temperature, the fusing lamp does not turn off for 12 consecutive seconds.
• Causes: - Fusing thermistor defective or out of position
  - Power supply board defective

• Code: 546
• Description: Unstable fusing temperature (center)
  The fusing temperature varies 50° C or more within 1 second, and this occurs 2 consecutive times.
• Causes: - Thermistor defective or out of position
  - Power supply unit defective

• Code: 547
• Description: Zero cross signal malfunction
  Zero cross signals are not detected within 5 seconds after the main power switch is turned on, or are not detected within 1 second after operation begins.
• Causes: - Power supply board defective
  - BICU defective

• Code: 551
• Description: Fusing thermistor open (rear)
  The fusing temperature detected by the thermistor is below 71°C and is not corrected after the main power switch is turned on.
• Causes: - Fusing thermistor defective or out of position
  - Power supply board defective
  - Loose connectors