• Code: 541
• Description: Fusing thermistor error
  The fusing temperature did not rise higher than 20C within 10 sec. after the main motor switched off. -or- The fusing temperature was detected lower than 0C 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 80oC 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 235C for longer than 200 ms.s
• 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 Hard
  During standby, the fusing temperature went below 60C twice or went above 60C three times within 500 ms.
• 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 condition