• Code: 545
• Description: Fusing overheat error 3 (center)
  After warmup, the center of the hot roller attained full operating temperature and maintained this temperature for 10 sec. without the hot roller rotating.
• Causes: • Center hot roller thermistor installed incorrectly, disconnected. • Center hot roller thermistor defective
• Remedy: 1. Check the hot roller thermistor is set correctly. 2. Replace the hot roller thermistor.

• Code: 547
• Description: 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 2 seconds even though the heater relay is on after turning on the main power or closing the front door.
• Causes: • Defective fusing lamp relay • Defective fusing lamp relay circuit • Unstable power supply
• Remedy: 1. Replace the fusing lamp relay. 2. Check the power supply source.

• Code: 551
• Description: Fusing thermistor open (end)
  The temperature of the hot roller remained below 0C for 5 sec. at the end of the hot roller.
• Causes: • Fusing thermistor out of its position because of incorrect installation • Fusing thermistor disconnected or defective • Power supply not within rated range (15% or more below rating)
• Remedy: 1. Check the fusing thermistor is set correctly. 2. Replace the fusing thermistor. 3. Check the power supply source.

• Code: 552
• Description: Fusing temperature warm-up error (end)
  The fusing temperature did not reach the standby temperature within 20 sec. at the center of the hot roller after the main switch turned on.
• Causes: • Fusing thermistor defective or out of position • Fusing lamp disconnected • Thermistor defective • Fusing lamp defective
• Remedy: 1. Check the fusing thermistor is set correctly. 2. Check the fusing lamp is connected correctly. 3. Replace the fusing thermistor. 4. Replace the fusing lamp.

• Code: 553
• Description: Fusing overheat error 1 (end)
  The fusing thermistor detected a fusing temperature over 230°C for 5 sec. at the center of the hot roller.
• Causes: • TRIAC short on PSU (PSU defective) • BCU board defective • Fusing thermistor defective
• Remedy: 1. Replace the PSU. 2. Replace the BCU board. 3. Replace the thermistor.

• Code: 554
• Description: Fusing overheat error 2 (end)
  A fusing temperature over 250°C is detected at the center of the hot roller by the fusing temperature monitor circuit in the BCU board. The power was interrupted for more than 0.3 sec.
• Causes: • TRIAC short on PSU (PSU defective) • BCU board defective • Fusing thermistor defective • Power supply voltage unstable
• Remedy: 1. Replace the PSU. 2. Replace the BCU board. 3. Replace the thermistor. 4. Check the power supply source.

• Code: 555
• Description: Fusing overheat error 3 (end)
  After warmup, the center of the hot roller attained full operating temperature and maintained this temperature for 10 sec. without the hot roller rotating.
• Causes: • Center hot roller thermistor installed incorrectly, disconnected. • Center hot roller thermistor defective
• Remedy: 1. Check the hot roller thermistor is set correctly. 2. Replace the hot roller thermistor.

• 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
• Remedy: Check the power supply source.