• Code: 541
• Description: Fusing thermistor error
  The fusing temperature did not rise higher than 20°C within 10 sec. after the main motor switched off. -or- The fusing temperature was detected lower than 0oC for over 1 sec. after the power relay switched on.
• Causes: • Thermistor disconnected, defective • Fusing lamp disconnected, defective • Fuse blown • Power supply board defective • Fusing unit connected improperly

• Code: 542
• Description: Fusing temperature warm-up error
  Just before reaching warm-up temperature, the fusing temperature did not rise above 80°C within 15.5 sec. after the power relay switched on.
• Causes: • Thermistor defective • Fusing lamp open • Fusing thermostat open • Power supply board Defective • Defective connection of the fusing unit

• Code: 543
• Description: Fusing overheat error – software
  The fusing temperature was detected higher than 235°C for longer than 200 ms.
• Causes: • Fusing thermistor defective. • Power supply board defective

• Code: 544
• Description: High temperature detection: Hard
  The thermister detects a high temperature signal
• Causes: • Defective thermister • Defective fusing unit, PSU, engine board

• Code: 545
• Description: Fusing lamp remains on
  The fusing lamp remained on longer than 12 sec. after the fusing unit reached optimum temperature and the main motor switched off.
• Causes: • Fusing thermistor defective • Power supply board defective • Defective connection of the fusing unit

• Code: 546
• Description: Unstable fusing temperature
  During standby, the fusing temperature went below 60°C twice or went above 60°C three times within 500 ms. A 60°C increase in fusing temperature was detected at five 1-sec. intervals within 60 sec. before reaching fusing temperature.
• Causes: • Fusing thermistor defective • Power supply board defective • Defective connection of the fusing unit

• Code: 547
• Description: Zero cross signal error
  Zero cross signals of wavelength 50-60 Hz were not detected within 5 sec after the fusing relay switched on. -or- Zero cross interrupts did not issue at the prescribed 3 sec. intervals.
• Causes: • Power supply board defective • Defective mains power supply condition

• Code: 559
• Description: Fusing unit jam
  Three consecutive paper lag jams (paper failed to arrive) were detected in the fusing unit. -or- During printing of the 1st side during duplexing, the paper did not arrive at the duplex entrance sensor three times.
• Causes: • Fusing unit installed incorrectly • Fusing unit defective