• Code: 541
• Description: Fuser thermistor error
  The thermistor output is less than 0°C for 5 seconds after the fusing lamp turns ON.
• Causes: • Disconnected or defective thermistor • Disconnected or defective fusing lamp 1. Check the harness connection of the thermistor. 2. Replace the fusing unit. • Execute "Reset Fusing Unit SC" to recover the machine after completing the recovery procedure. Otherwise, the machine continues to issue this SC code and cannot be operated.

• Code: 542
• Description: Fuser reload error
  This SC is issued if one of following conditions occurs: The fusing temperature rises 8°C or less in 1.5 seconds; and this continues 5 times consecutively. -or- The fusing temperature has not reached 45°C within 9 seconds (after the fusing lamp comes ON while the machine is warming-up). -or- The fusing unit does not attain reload temperature within 35 s. (normal temperature) or 65 s (lower temperature – the thermistor output is less than 18°C) after the fusing temperature control starts.
• Causes: • Defective or deformed thermistor • Incorrect power supply input at the main power socket 1. Defective fusing lamp

• Code: 543
• Description: High temperature error (Software)
  • The detected temperature stays at 225°C for 1 second, and this consecutively occurs 10 times.
• Causes: • Defective ECB • Defective PSU 1. Replace the ECB 2. Replace the PSUt unit. • Execute "Reset Fusing Unit SC" to recover the machine after completing the recovery procedure. Otherwise, the machine continues to issue this SC code and cannot be operated.

• Code: 544
• Description: High temperature error (Hardware)
  • During stand-by mode or a print job, the detected heating roller temperature reaches 250° C.
• Causes: • Defective ECB • Defective PSU 1. Replace the ECB 2. Replace the PSU • Execute "Reset Fusing Unit SC" to recover the machine after completing the recovery procedure. Otherwise, the machine continues to issue this SC code and cannot be operated.

• Code: 545
• Description: Fusing Lamp Overheat Error
  The fusing lamps remained ON at full capacity for more than 9 s after the fusing temperature attains reload temperature.
• Causes: • Deformed thermistor • Thermistor not in the correct position • Defective fusing lamp 1. Replace the fusing unit. 2. Replace the fusing lamp. • Execute "Reset Fusing Unit SC" to recover the machine after completing the recovery procedure. Otherwise, the machine continues to issue this SC code and cannot be operated.

• Code: 547
• Description: Zero cross error
  • The zero cross signal is detected three times even though the fusing lamp relay is off when turning on the main power. • The zero cross signal is not detected for 3 seconds even though the fusing lamp relay is on after turning on the main power or closing the front door. • The detection error occurs twice or more in 11 zero cross signal detections. This error is defined when the detected zero cross signal is less than 45. • The zero cross signal is not detected three times while the main power remains ON.
• Causes: • Defective fusing relay • Defective fusing relay circuit • Shorted +24V fuse on the PSU • Unstable power supply. 1. Check the power supply source. 2. Replace the +24V fuse on the PSU. 3. Replace the PSU

• Code: 557
• Description: Zero cross frequency error
  The zero cross signal is detected ten times while the fusing lamp relay remains ON after turning on the main power.
• Causes: • Defective fusing lamp relay • Defective drive circuit of the fusing lamp relay • Unstable input power source 1. Check the power supply source. 2. Replace the fusing unit. • Execute "Reset Fusing Unit SC" to recover the machine after completing the recovery procedure. Otherwise, the machine continues to issue this SC code and cannot be operated.

• Code: 559
• Description: Fuser 3times jam error
  The paper jam counter for the fusing unit reaches 3. The paper jam counter is cleared if the paper is fed correctly. This SC is activated only when this function is enabled with "Engine Maintenance" (default "OFF").
• Causes: • Defective fusing unit • Defective fusing control 1. Clear this SC to send a command after a jam removal. 2. Turn off this function after a jam removal. • Execute "Reset Fusing Unit SC" to recover the machine after completing the recovery procedure. Otherwise, the machine continues to issue this SC code and cannot be operated.