• Code: 542
• Description: Heating roller warm-up error 1
  • The heating roller temperature does not reach the ready temperature for 190 seconds after the IH inverter turns on. • The heating roller temperature does not reach 80°C for 18 seconds after the IH inverter on.
• Causes: • Dirty or defective thermopile • Defective IH coil unit
• Remedy: 1. Check if the heating roller thermopile is firmly connected. 2. Replace the thermopile. 3. Replace the IH coil unit.

• Code: 543
• Description: Heating roller overheat 1 (software error)
  The detected fusing temperature stays at 215°C for 1 second.
• Causes: • Defective PSU • Defective IOB • Defective EGB
• Remedy: 1. Replace the PSU. 2. Replace the IOB. 3. Replace the BCU.

• Code: 544
• Description: Heating roller overheat 1 (hardware error)
  During stand-by mode or a print job, the detected heating roller temperature reaches 220 °C.
• Causes: • Defective PSU • Defective IOB • Defective EGB • Defective fusing control system
• Remedy: 1. Replace the PSU. 2. Replace the IOB. 3. Replace the BCU.

• 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 3 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 39.
• Causes: • Defective fusing relay • Defective fusing relay circuit • Shorted +24V fuse on the PSU • Unstable power supply
• Remedy: 1. Check the power supply source. 2. Replace the +24V fuse on the PSU. 3. Replace the PSU

• Code: 548
• Description: Fusing unit rotation error
  The fusing belt sensor does not detect change in the actuator for 0.5 seconds after the fusing/paper exit motor has turned on.
• Causes: • Defective fusing/paper exit motor • Deformed actuator for the fusing belt sensor • Defective fusing belt sensor • Broken connection between IH inverter and IOB • Incorrectly set fusing unit
• Remedy: 1. Check if the fusing unit is correctly set. 2. Check or replace the actuator for heating roller rotation sensor. 3. Replace the heating roller rotation sensor. 4. Replace the IH inverter. 5. Check the connection between IH inverter and IOB.

• Code: 551
• Description: Heating roller thermistor error
  The temperature measured by the heating roller thermistor does not reach 0 °C for 7 seconds.
• Causes: • Loose connection of heating roller thermistor • Defective heating roller thermistor
• Remedy: 1. Check that the heating roller thermistor is firmly connected. 2. Replace the heating roller thermistor.

• Code: 552
• Description: Heating roller warm-up error 2
  • The heating roller temperature does not reach the ready temperature for 90 seconds after the heating lamp on. • The heating roller temperature does not reach 80°C for 13 seconds after the IH inverter on.
• Causes: • Defective thermistor • Defective IH inverter
• Remedy: 1. Check if the heating roller thermistor is firmly connected. 2. Replace the IH inverter.

• Code: 553
• Description: Heating roller overheat (software error)
  The detected heating roller temperature stays at 230°C or more for 1 second.
• Causes: • Defective PSU • Defective IOB • Defective EGB
• Remedy: 1. Replace the PSU. 2. Replace the IOB. 3. Replace the BCU.