• Code: 544
• Description: Fusing sleeve belt overheat: Center (hardware error)
  During stand-by mode or a print job, the detected fusing sleeve belt temperature reaches 250°C.
• Causes: Defective PSU. Defective BCU. Defective AC control board. Defective IOB. Defective fusing control system.
• Remedy: • Replace the PSU. • Replace the BCU. • Replace the AC controller board. • Replace the IOB. Replace the fusing unit and reset the counter of the fusing unit using SP3-902-014. Important: • The fusing unit cannot be used because an abnormal high temperature was detected. After this SC occurs, the counter reset of the fusing unit should be done manually using SP3-902-014 because the counter reset is not done automatically. • After replacing fusing unit, to set SP5-810-2 is necessary to reset this SC.

• Code: 545
• Description: Fusing Heater error: Center
  The fusing heater keeps full power for 9 seconds or more.
• Causes: Defective thermistors. Broken heater cables. This is determined after the device for preventing excessive temperature rise operates.
• Remedy:

• Code: 547
• Description: Zero cross error
  After the zero-crossing interrupt setting is enabled, the machine waits for 50+-20 ms. If a request for zero-crossing interrupt is received while waiting, the machine retries the search after the waiting time is completed. The detection occurs consecutively 3 times.
• Causes: Defective fusing relay. Defective fusing relay circuit.
• Remedy: • Turn the main power switch off and on. • If the fusing relay is damaged, replace the PSU. • Check the connection between the PSU and control board, and then replace the harness and board if necessary.

• Code: 549
• Description: Fusing heater connection error
  The fusing sleeve belt rotation sensor detects the target temperature as 50°C for 5 seconds or more after the fusing/paper exit motor has turned on.
• Causes: Broken heater cables. Loose connection.
• Remedy:

• Code: 551
• Description: Fusing sleeve belt thermistor error
  The temperature at the end of the fusing sleeve belt measured by the fusing sleeve belt thermistor does not reach -50°C for 0.1 seconds.
• Causes: Defective thermopile. Defective thermistor. Loose connection.
• Remedy:

• Code: 552
• Description: Fusing sleeve belt warm-up error 2
  The fusing sleeve belt temperature does not reach 81C for 6 seconds after the inverter turned on.)
• Causes: Dirty thermopile lenses. Deformed thermistor.
• Remedy:

• Code: 553
• Description: Fusing sleeve belt overheat: End (software error)
  The detected fusing sleeve belt temperature stays at 240°C or more for 1 second for 10 consecutive times.
• Causes: The triac switch has shorted out. Defective IOB. Defective BCU.
• Remedy:

• Code: 554
• Description: Fusing sleeve belt overheat: End (hardware error)
  The fusing sleeve belt thermistor detects 250°C or more.
• Causes: Defective PSU. Defective BCU. Defective AC control board. Defective IOB. Defective fusing control system.
• Remedy: • Replace the PSU. • Replace the BCU. • Replace the AC controller board. • Replace the IOB. • Replace the fusing unit and reset the counter of the fusing unit using SP3-902-014. Important: The fusing unit cannot be used because an abnormal high temperature was detected. • After this SC occurs, the counter reset of the fusing unit should be done manually using SP3-902-014 because the counter reset is not done automatically. • After replacing fusing unit, to set SP5-810-2 is necessary to reset this SC.