• Code: 543
• Description: Fusing overheat error 1
  A fusing temperature over 230°C is detected for 5 second by the fusing thermistor.
• Causes: • TRIAC short on PSU (PSU defective) • SBCU board defective • Fusing thermistor defective

• Code: 544
• Description: Fusing overheat error 2
  • A fusing temperature over 250°C is detected by the fusing temperature monitor circuit in the SBCU board. • The power was interrupted for more than 0.3 sec.
• Causes: • TRIAC short on PSU (PSU defective) • SBCU board defective • Fusing thermistor defective • Voltage of power supply unstable

• Code: 545
• Description: Fusing overheat error 3
  After warmup, the hot roller attained full operating temperature and maintained this temperature for 10 sec. without the hot roller rotating.
• Causes: • Hot roller thermistor is out of its position because of incorrect installation

• Code: 546
• Description: Unstable fusing temperature
  The fusing temperature varies 50°C or more twice in succession within 1 sec.
• Causes: • Thermistor disconnected or defective • Fusing unit drawer installed incorrectly

• Code: 547
• Description: Zero cross signal detection error
  Zero cross signals are not detected within a certain period.
• Causes: • PSU defective • SBCU board defective

• Code: 548
• Description: Fusing unit set error
  The machine does not detect the fusing unit.
• Causes: • Poor connection of the fusing unit • The fusing unit is not installed

• Code: 557
• Description: Zero cross waveform signal error
  The waveform of the zero cross signal was detected out of range.
• Causes: • Electrical noise on the power supply line

• Code: 590
• Description: Exhaust fan motor error
  The CPU detects an exhaust fan lock signal for more than 3.5 seconds.
• Causes: • Poor connection of the exhaust fan motor • Too much load on the motor drive