• Code: 543
• Description: Fusing overheat error 1 (software detection)
  A fusing temperature (at the center) of over 230 °C (446 °F) is detected for 1 second by the fusing thermistors at the center or at either end of the fusing roller.
• Causes: • Power supply unit defective • I/O board (IOB) defective • BICU defective • TRIAC short on PSU (PSU defective)

• Code: 544
• Description: Fusing overheat error 1 (hardware detection)
  A fusing temperature (at the center) over 250 °C is detected by the fusing temperature monitor circuit in the BICU board.
• Causes: • I/O board (IOB) defective • BICU defective

• Code: 545
• Description: Fusing lamp consecutive full power 1
  After warm-up the fusing lamp remains at full power for 15 seconds without the hot roller rotating.
• Causes: • Disconnected or defective thermistors (center) • Defective fusing lamp

• Code: 547
• Description: Zero cross error
  • The zero cross signal is detected three times even though the heater relay is off when turning on the main power. • The zero cross signal is not detected for 2 seconds even though the heater relay is on after turning on the main power or closing the front door. • The detection error occurs twice or more in the 11 zero cross signal detections. This error is defined when the detected zero cross signal is less than 45.
• Causes: • Defective fusing lamp relay • Defective fusing lamp relay circuit • Unstable power supply

• Code: 551
• Description: Fusing thermistor open (end)
  The thermistor (end) detects 0°C or less for 5 sec.
• Causes: • Fusing thermistor (end) disconnected • Fusing thermistor (end) connector defective

• Code: 552
• Description: Fusing temperature warm-up error (end)
  This SC is generated if the following condition occurs:
  • The thermistor (end) does not detect an 8°C increment in the fusing temperature for 7.5 sec. just after the fusing temperature reached 45 °C.
  • The temperature of the end thermistor does not reach the target temperature for 31 seconds after the fusing lamps turned on.
• Causes: • Thermistor warped or broken

• Code: 553
• Description: Fusing overheat error 1 (software detection)
  A fusing temperature (at the end) of over 230 °C (446 °F) is detected for 1 second by the fusing thermistors at the center or at either end of the fusing roller.
• Causes: • Power supply unit defective • I/O board (IOB) defective • BICU defective • TRIAC short on PSU (PSU defective)

• Code: 554
• Description: Fusing overheat error 1 (hardware detection)
  A fusing temperature (at the end) over 250 °C is detected by the fusing temperature monitor circuit in the BICU board.
• Causes: • I/O board (IOB) defective • BICU defective