• Code: 541
• Description: Heating roller error 1 The temperature detected by the thermopile does not reach 0°C for 6 seconds.
• Causes: • Loose connection of the thermopile • Defective thermopile
• Remedy: 1. Check that the thermopile is firmly connected. 2. Replace the thermopile.

• Code: 542
• Description: Heating roller warm-up error 1
  • After the main switch is turned on or the cover is closed, the increment of the heating roller temperature per 10 seconds is 30°C or less. If this condition is detected five times consecutively, SC 542 is defined. • The heating roller temperature does not reach 100°C for 15 seconds after the heating lamp on. • The heating roller temperature does not reach the ready temperature while 60 seconds after the heating lamp on. • The center temperature of the heating roller does not reach the ready temperature for 30 seconds after the edge temperature of the heating roller has reached the ready temperature
• Causes: • Dirty or defective thermopile • Defective thermopile. • Trash on the surface of the thermopile lens. • Defected thermistor. • Input voltage is over guaranteed value • Defective heating roller lamp
• Remedy: 1. Check if the thermopile is firmly connected. 2. Clean the surface of the thermopile lens. 3. Test the conductance for the thermopile and the heating roller 4. Replace the thermopile. 5. Replace the heating roller lamp.

• Code: 543
• Description: Heating roller fusing lamp overheat 1 (software error)
  The detected fusing temperature stays at 230°C for 1 second.
• Causes: • Defective PSU • Defective BCU
• Remedy: 1. Replace the PSU. 2. Replace the BCU.

• Code: 544
• Description: Heating roller fusing lamp overheat 1 (hardware error)
  During stand-by mode or a print job, the detected heating roller temperature reaches 250 °C.
• Causes: • Defective PSU • Defective BCU • Defective heating roller thermistor (end) • Defective fusing control system
• Remedy: 1. Replace the PSU. 2. Replace the BCU. 3. Replace the heating roller thermistor (end).

• Code: 545
• Description: Heating roller fusing lamp consecutive full power 1
  When the fusing unit is not running in the ready condition, the heating roller fusing lamp keeps on full power for 8 seconds.
• Causes: • Broken heating roller thermostat • Broken heating roller fusing lamp
• Remedy: 1. Replace the heating roller thermistor. 2. Replace the heating roller fusing lamp.

• Code: 547
• Description: Zero cross error
  • The zero cross signal is detected for 0.05 seconds three times even though the heater relay is off when turning on the main power. • The zero cross signal is not detected for 3 seconds even though the heater relay is on after turning on the main power or closing the front door. • The detection error occurs twice or more in the 11 zero cross signal detections. This error is defined when the detected zero cross signal is less than 45.
• Causes: • Defective fusing lamp relay • Defective fusing lamp relay circuit • Unstable power supply
• Remedy: 1. Check the power supply source. 2. Replace the shorted 24V fuse on the PSU. 3. Replace the PSU

• Code: 551
• Description: Heating roller thermistor (end) error 2
  • The temperature measured by the heating roller thermistor (end) does not reach 0°C for 6 seconds.
• Causes: • Loose connection of heating roller thermistor (end) • Defective heating roller thermistor (end)
• Remedy: 1. Check that the heating roller thermistor (end) is firmly connected. 2. Replace the heating roller thermistor (end).

• Code: 552
• Description: Heating roller warm-up error 2
  The heating roller temperature does not reach the ready temperature while 70 seconds after the heating lamp on.
• Causes: • Dirty or defective thermistor (end) • Heating roller fusing lamp broken • Defected thermostat • Defective heating roller fusing lampamp on.
• Remedy: 1. Check if the heating roller thermistor (end) is firmly connected. 2. Replace the heating roller thermistor (end). 3. Replace the heating roller fusing lamp.