• Code: 542
• Description: Fusing temperature warm-up error
  One of the following occurred:
  • After power on, or after closing the front door, the hot roller does not reach the 100°C control temperature within 25 s.
  • 5 sec. after temperature rise started, temperature remained below 21°C after 5 samplings.
  • Fusing unit did not attain reload temperature within 48 sec. of the start of fusing temperature control.
• Causes: • Fusing lamp disconnected
  • Thermistor warped, out of position
  • Thermostat not operating

• Code: 543
• Description: Fusing lamp overheat error 1 (software)
  Central thermistor detected a temperature of 240°C at the center of the hot roller. Fusing temperature control software error
• Causes: • PSU defective
  • IOB defective
  • BICU defective

• Code: 544
• Description: Fusing lamp overheat error 1 (hardware)
  The central thermistor or an end thermistor detected a temperature of 250°C on the hot roller.
• Causes: • PSU defective
  • IOB defective
  • BICU defective

• Code: 545
• Description: Fusing lamp overheat error 2
  After hot roller reaches warmup temperature, the fusing lamps remained on at full capacity for 11 samplings (1.8 sec. duration) while the hot roller was not rotating.
• Causes: • Thermistor damaged, or out of position
  • Fusing lamp disconnected

• Code: 547
• Description: Zero cross signal malfunction
  One of the following conditions is detected 10 times:
  • When the main switch is on, the frequency measured by the number of zero cross signals for 500 ms is larger than 66Hz or smaller than 45 Hz.
  • The interval between one zero cross signal and the next is 7.5 ms or shorter 3 times consecutively for 500 ms.
• Causes: • Noise on the ac power line

• Code: 550
• Description: Fusing Web End
  Web end detected 5 times within 500 ms and web motor continues to rotate 40 s. If web end is detected for another 500 ms, then the SC is logged.
• Causes: • Web end (requires replacement)
  • Web end sensor defective Note: After replacing the web with a new one, reset SP1902 001 to "0" to release SC550.

• Code: 551
• Description: Fusing thermistor error 1
  The end thermistor (contact type) was less than 0C (32F) for more than 7 seconds.
• Causes: • Thermistor disconnected
  • Thermistor connector defective

• Code: 552
• Description: Fusing thermistor error 2
  The end thermistor (contact type) could not detect:
  • 100°C 25 seconds after the start of the warmup cycle.
  • A change in temperature more than than 16 degrees for 5 seconds.
  • The reload temperature with 56 seconds after the start of the fusing temperature control cycle.
• Causes: • Fusing lamp disconnected
  • Thermistor bent, damaged
  • Thermistor position incorrect