• Code: 544
• Description: Fusing overheat error (hardware circuit detection)
  The dual monitoring circuitry of the BICU detected temperature above 250oC (482oF) and tripped the relay circuit off.
• Causes: • Check harnesses and connectors of PSU, IOB, BICU • PSU defective • IOB defective • BICU defective • Fusing thermistor defective or wrong type

• Code: 545
• Description: Fusing lamp remains on
  After warm-up the fusing lamp remained at full power for 10 sec. (center) and 15 sec. (ends) without the hot roller rotating.
• Causes: • One or both thermistors out of position.

• Code: 547
• Description: Zero cross signal error
  One of the following occurred: 1. The fusing relay remained off for 50 ms after power on and continued to remain off after the after 3 attempts to detect the zero-cross signal. 2. During 11 zero-cross signal detections, two zero-cross signal detections were below 44 Hz. 3. The zero-cross signal could not be detected within 3 sec. after the fusing relay switched on.
• Causes: • PSU defective • Noise on the ac power line

• Code: 548
• Description: Fusing unit installation error
  The machine cannot detect the fusing unit when the front cover and right cover are closed.
• Causes: • Fusing unit is not installed • Fusing unit connection loose

• Code: 557
• Description: Zero-cross frequency over
  The applied power ac frequency was detected less than 66 Hz more than 10 times, or less than 44 Hz one time.
• Causes: • Noise on the ac power line

• Code: 559
• Description: Fusing unit jam
  The fusing exit sensor detected a fusing unit paper late jam three times. The paper was late and the fusing exit sensor could not detect the paper three times.
• Causes: • Remove the paper that is stopped in the fusing unit. • Check that the fusing unit is clean and has no obstacles in the paper feed path. • If the error persists, replace the fusing unit

• Code: 620
• Description: Communication timeout error between BICU and finisher
  The BICU did receive a response within 100 ms after 3 attempts after sending data to the finisher.
• Causes: • Serial line connecting BICU and finisher unstable • External noise • BICU board and finisher main board connection defective or loose • Finisher main board defective • BICU board defective

• Code: 621
• Description: Communication timeout error between BICU and finisher
  A break (low) signal was received from the finisher.
• Causes: • Serial line connecting BICU and finisher unstable • External noise • BICU board and finisher main board connection defective or loose • Finisher main board defective • BICU board defective