• Code: 6F00
• Description: The center thermistor or the side thermistor of the fuser unit detected a temperature error.
• Causes: 1 Connection failure of the center or side thermistor harness of the fuser unit. 2 Connection failure of the heater harness of the fuser unit. 3 Connection failure of the eject sensor PCB harness. 4 Connection failure of the lowvoltage power supply PCB harness. 5 Eject sensor PCB failure. 6 Fuser unit failure. 7 Low-voltage power supply PCB failure. 8 Main PCB failure.
• Remedy: 1 Connection failure of the center or side thermistor harness of the fuser unit Check the connection of the center or side thermistor harness of the fuser unit, and reconnect it if necessary. 2 Connection failure of the heater harness of the fuser unit Check the connection of the heater harness of the fuser unit, and reconnect it if necessary. 3 Connection failure of the eject sensor PCB harness Check the connection of the eject sensor PCB harness, and reconnect it if necessary. 4 Connection failure of the lowvoltage power supply PCB harness Check the connection of the low-voltage power supply PCB harness, and reconnect it if necessary. 5 Eject sensor PCB failure Refer to "1.3.10 Check sensor operation (function code: 32)" in Chapter 5 to check the sensor operation. If the sensor operation is faulty, replace the eject sensor PCB ASSY. 6 Fuser unit failure Replace the fuser unit. 7 Low-voltage power supply PCB failure Replace the low-voltage power supply PCB ASSY. 8 Main PCB failure Replace the main PCB ASSY.

• Code: 7100
• Description: Detected an error in the synchronized signal of the polygon motor for the laser unit.
• Causes: 1 Connection failure of the laser unit flat cable. 2 Laser unit failure. 3 Main PCB failure.
• Remedy: 1 Connection failure of the laser unit flat cable Check the connection of the laser unit flat cable, and reconnect it if necessary. 2 Laser unit failure Replace the laser unit. 3 Main PCB failure Replace the main PCB ASSY.

• Code: 7200
• Description: Cannot detect the signal from the beam detecting sensor for the laser unit.
• Causes: 1 Connection failure of the laser unit flat cable. 2 Laser unit failure. 3 Main PCB failure.
• Remedy: 1 Connection failure of the laser unit flat cable Check the connection of the laser unit flat cable, and reconnect it if necessary. 2 Laser unit failure Replace the laser unit. 3 Main PCB failure Replace the main PCB ASSY.

• Code: 7500
• Description: The internal temperature thermistor detected a temperature higher than the specified value.
• Causes: 1 Internal temperature thermistor failure. 2 Main PCB failure.
• Remedy: 1 Internal temperature thermistor failure Replace the Internal temperature thermistor. 2 Main PCB failure Replace the main PCB ASSY.

• Code: 7600
• Description: The center thermistor of the fuser unit detected a temperature rise greater than the specified value within the specified time.
• Causes: 1 Connection failure of the center or side thermistor harness of the fuser unit. 2 Connection failure of the heater harness of the fuser unit. 3 Connection failure of the eject sensor PCB harness. 4 Connection failure of the lowvoltage power supply PCB harness. 5 Eject sensor PCB failure. 6 Low-voltage power supply PCB failure. 7 Main PCB failure.
• Remedy: 1 Connection failure of the center or side thermistor harness of the fuser unit Check the connection of the center or side thermistor harness of the fuser unit, and reconnect it if necessary. 2 Connection failure of the heater harness of the fuser unit Check the connection of the heater harness of the fuser unit, and reconnect it if necessary. 3 Connection failure of the eject sensor PCB harness Check the connection of the eject sensor PCB harness, and reconnect it if necessary. 4 Connection failure of the lowvoltage power supply PCB harness Check the connection of the low-voltage power supply PCB harness, and reconnect it if necessary. 5 Eject sensor PCB failure Refer to "1.3.10 Check sensor operation (function code: 32)" in Chapter 5 to check the sensor operation. If the sensor operation is faulty, replace the eject sensor PCB ASSY. 6 Low-voltage power supply PCB failure Replace the low-voltage power supply PCB ASSY. 7 Main PCB failure Replace the main PCB ASSY.

• Code: 7800
• Description: The center thermistor of the fuser unit detected a temperature fall greater than the specified value within the specified time.
• Causes: 1 Connection failure of the center or side thermistor harness of the fuser unit. 2 Connection failure of the heater harness of the fuser unit. 3 Connection failure of the eject sensor PCB harness. 4 Connection failure of the lowvoltage power supply PCB harness. 5 Eject sensor PCB failure. 6 Low-voltage power supply PCB failure. 7 Main PCB failure.
• Remedy: 1 Connection failure of the center or side thermistor harness of the fuser unit Check the connection of the center or side thermistor harness of the fuser unit, and reconnect it if necessary. 2 Connection failure of the heater harness of the fuser unit Check the connection of the heater harness of the fuser unit, and reconnect it if necessary. 3 Connection failure of the eject sensor PCB harness Check the connection of the eject sensor PCB harness, and reconnect it if necessary. 4 Connection failure of the lowvoltage power supply PCB harness Check the connection of the low-voltage power supply PCB harness, and reconnect it if necessary. 5 Eject sensor PCB failure Refer to "1.3.10 Check sensor operation (function code: 32)" in Chapter 5 to check the sensor operation. If the sensor operation is faulty, replace the eject sensor PCB ASSY. 6 Low-voltage power supply PCB failure Replace the low-voltage power supply PCB ASSY. 7 Main PCB failure Replace the main PCB ASSY.

• Code: 7A00
• Description: Cannot detect the synchronized signal of the main motor. The speed of the main motor does not stabilize within the specified time.
• Causes: 1 Connection failure of the main motor harness. 2 Main motor failure. 3 Main PCB failure.
• Remedy: 1 Connection failure of the main motor harness Check the connection of the main motor harness, and reconnect it if necessary. 2 Main motor failure Replace the main motor ASSY. 3 Main PCB failure Replace the main PCB ASSY.

• Code: 7D00
• Description: Detected discharge that may be attributable to dirty corona wire on the drum unit.
• Causes: 1 High-voltage power supply PCB failure. 2 Main PCB failure.
• Remedy: 1 High-voltage power supply PCB failure Replace the high-voltage power supply PCB ASSY. 2 Main PCB failure Replace the main PCB ASSY.