• Code: 6400
• Description: Zero-cross signal error During the heater turned on, the zero-cross signal disappears for consecutive 1s
• Remedy: Low voltage power supply PWB Replace the low voltage power supply PWB.
  Main/Engine PWB Replace the main/engine PWB.

• Code: 6600
• Description: Fuser rotation error The fuser roller rotation detection is not input for consecutive 2s while the motor's steady signal is input
• Remedy: Fuser unit 1. Make sure there is no paper jam. 2. Confirm that the wiring connector is firmly connected, and if necessary, connect the connector all the way in. Fuser unit - Main/Engine PWB(YC19) 3. If the wiring is disconnected, shortcircuited or has a ground fault, replace the wire. 4. Replace the fuser unit.
  Main/Engine PWB Replace the main/engine PWB.

• Code: 6610
• Description: The fuser pressure release error The fuser pressure change is not complete within 10s after the instruction
• Remedy: Fuser unit 1. Make sure there is no paper jam. 2. Confirm that the wiring connector is firmly connected, and if necessary, connect the connector all the way in. Fuser unit - Main/engine PWB (YC19) 3. If the wiring is disconnected, shortcircuited or has a ground fault, replace the wire. 4. Replace the fuser unit.
  Fuser pressure release error 1. Reverse-rotate the fuser gear manually to check if the fuser pressure can be released. 2. When releasing the pressure, check the fuser pressure release sensor is interrupted by the actuator Reattach it if the light is not interrupted 3. Reconnect the wire connector Replace the wire if there is no continuity. Fuser pressure release sensor - Main/ engine PWB (YC19) Fuser pressure release motor - Main/ engine PWB (YC1) 4. Replace the fuser pressure release motor.
  Main/Engine PWB Replace the main/engine PWB.

• Code: 6650
• Description: Fuser thermopile EEPROM error 1. The thermopile EEPROM is not accessed 2. No response from the device at read was detected five time consecutively Data read at two points was unmatched eight times consecutively 3. Thermopile data checksum error
• Remedy: Thermopile 1. Reconnect the wire connector Replace the wire if there is no continuity. 2. Thermopile - Main/engine PWB (YC2) 3. Replace the thermopile if not repaired
  Main/Engine PWB Replace the main/engine PWB.

• Code: 7220
• Description: Broken in-machine thermistor wire The sensor input sampling value is greater than the reference value.
• Remedy: In-machine temperature sensor 1. Confirm that the wiring connector is firmly connected, Insert the connector all the way in. In-machine temperature sensor - Main/engine PWB (YC1) 2. If the wiring is disconnected, shortcircuited or has a ground fault, replace the wire. Replace the in-machine temperature sensor PWB.
  Main/Engine PWB Replace the main/engine PWB.

• Code: 7800
• Description: Broken outer thermistor wire The sensor input sampling value is abnormal. (After detecting an error, it is controlled at 23°C/77 °F and 50%RH)
• Remedy: Temperature and humidity Sensor 1. Confirm that the wiring connector is firmly connected, and if necessary, connect the connector all the way in. Temperature and humidity sensor - Main/engine PWB (YC2) 2. If the wiring is disconnected, shortcircuited or has a ground fault, replace the wire. 3. Replace the Temperature and humidity sensor PWB.
  Main/Engine PWB Replace the main/engine PWB.

• Code: 7990
• Description: Waste toner full The waste toner sensor detected the waste toner reservoir in the drum unit is full
• Remedy: Drum unit Turn the power switch off and on Replace the drum unit if not repaired.
  Waste toner sensor Replace the waste toner sensor.
  Main/Engine PWB Replace the main/engine PWB.

• Code: F000
• Description: Communication error between Main/Engine PWB - Operation panel PWB
• Remedy: Connection of the wires and connectors between the main/engine PWB - the operation panel PWB. If the connector is not inserted enough, reinsert it. Or check the wire's continuity, and repair or replace the wire if there is no continuity.
  Operation panel PWB Replace the operation panel PWB.
  Main/Engine PWB Replace the main/engine PWB.