• Code: 531
• Description: Fusing exit motor error
  The PLL lock signal was low for 2 seconds during motor operation.
• Causes: • Motor lock caused by physical overload • Motor drive PCB defective

• Code: 541
• Description: Fusing thermistor open
  The fusing temperature detected by the center thermistor was below 0°C for 7 sec.
• Causes: • Thermistor open • Thermistor connector defective • Thermistor damaged, or out of position • Fusing temperature –15% less than the standard input voltage

• 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 center 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.