• Code: C6920
• Description: Eject/IH fan motor error
• Causes: The lock-up was detected for 20s continuously when driving the fan motor.
• Remedy: 1 Checking the wire The wire is not properly connected or is faulty. Execute U037 to check the operation of the eject/IH fan motors. If they do not operate properly, reconnect the following wire connectors. If there is no continuity, replace the wires.• Front/Middle/Rear eject IH fan motors - Feed image PWB• Feed image PWB - Engine PWB Electrical Diagram of PWBs 2 Checking the eject/IH fan motors The eject/IH fan motors do not properly operate. Clean the following fan motors, and remove foreign material if it adheres on the fan motors. Then, replace the fan motors if they are not fixed.• Front eject/IH fan motor• Middle eject/IH fan motor• Rear eject/IH fan motor 3 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 4 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB. 5 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement

• Code: C6950
• Description: IH PWB communication error
• Causes: 1. The communication between the IH PWB and the engine PWB does not succeed at the initial communication. (The retry is executed 10 times in 150ms intervals.)2. The communication between the IH PWB and the engine PWB does not succeed for 500ms after the initial communication success.
• Remedy: 1 Resetting the main power The power startup delays. Turn the power switch and the main power switch off . After 5s passes, turn the main power switch and the power switch on. 2 Checking the wire The wire is not properly connected or is faulty. Reinsert the following wire connectors, and replace the wire when it has no continuity.• IH PWB - Engine PWB Electrical Diagram of PWBs 3 Checking the wire The wire is not properly connected or is faulty. Reinsert the following wire connectors, and replace the wire when it has no continuity.• LVU - IH PWB Electrical Diagram of PWBs 4 Checking the power supply voltage The abnormal electric noise is mixed in the power supply voltage. Plug the power cord into another wall outlet. 5 Checking the LVU The fuse on the LVU is broken. Check the continuity of the fuse (F002) on the LVU. Then, replace the LVU if there is no continuity. LVU Replacement 6 Replacing the IH PWB The IH PWB is faulty. Replace the IH PWB. IH PWB Replacement 7 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 8 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement

• Code: C6980
• Description: Fuser unit EEPROM error
• Causes: The EEPROM in the fuser unit cannot be accessed since the machine condition matches to either of the following. 1. No response from the device is detected for 5s or more 5 times continuously when reading / writing the data.2. The reading data of 2 points mismatches 8 times continuously.3. The reading data and the writing data mismatch 8 times continuously.
• Remedy: 1 Reinstalling the fuser unit The drawer connector of the fuser unit is not properly inserted. Check if the pins of the drawer connector of the fuser unit do not bend. If it bend, replace the fuser unit. When the pins are proper, reinstall the fuser unit so that the drawer connector firmly connects. Fuser Unit Replacement 2 Replacing the fuser unit The fuser unit is faulty. Replace the fuser unit. Fuser Unit Replacement 3 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement 4 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB.

• Code: C6990
• Description: Fuser power source destination error
• Causes: The information mismatches between the engine backup and the IH PWB.
• Remedy: 1 Executing U169 The voltage setting at U169 mismatches the voltage of the IH PWB. Set the destination same as the voltage of the IH PWB at U169. U169 Execution 2 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 3 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement

• Code: C7001
• Description: Container motor error
• Causes: 1. The ready signal does not turn on after passing 2s since the container motor was started up.2. The ready signal is off for 2s continuously after the container motor was stabilized.
• Remedy: Replacing the toner container The toner container locks up and is not rotated. Replace the toner container. Toner Container Replacement 2 Checking the toner container drive components The toner container drive components are not operated properly, or the excessive load is applied to it. Check the container motor operation by executing U030 [Container Mix]. If it does not operate properly, clean the drive gears and the couplings in the container drive unit and apply the grease to them. U030 Execution 3 Checking the wire The wire is not properly connected or is faulty. Reinsert the following wire connectors, and replace the wire when it has no continuity.• Container motor - Feed image PWB Electrical Diagram of PWBs 4 Checking the toner container motor The toner container motor is faulty. Reattach the container motor and reconnect the wire. Replace it if it is not fixed. Container Motor Replacement 5 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 6 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB.

• Code: C7101
• Description: T/C sensor BK error
• Causes: For the specified value of the initial toner stored in the EEPROM of the developer unit, the output value of the T/C sensor is out of the range between +100 (undetection toner) and -1000 (Coming off of the sensor connector). And that status was detected 3 times continuously.
• Remedy: 1 Reinstalling the developer unit The developer unit is not properly installed. Reinstall developer unit BK so that the connector firmly connects. Developer Unit Replacement 2 Checking the wire The wire is not properly connected or is faulty. Reinsert the following wire connectors, and replace the wires when they have no continuity.• Drum/developer relay PWB - Feed image PWB• Feed image PWB - Engine PWB Electrical Diagram of PWBs 3 Replacing the drive gear The drive gear for developer unit BK is damaged. (The spiral is not rotated.) Replace the drive gear for developer unit BK. 4 Developer unit replacement Developer unit BK (T/C sensor BK) is faulty. Replace the developer unit BK. Developer Unit Replacement 5 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 6 Replacing the drum/developer relay PWB The drum/developer relay PWB is faulty. Replace the drum/developer relay PWB. Drum/ Developer Relay PWB Replacement 7 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB. 8 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement

• Code: C7102
• Description: T/C sensor C error Object: Color models
• Causes: For the specified value of the initial toner stored in the EEPROM of the developer unit, the output value of the T/C sensor is out of the range between +100 (undetection toner) and -1000 (Coming off of the sensor connector). And that status was detected 3 times continuously
• Remedy: 1 Reinstalling the developer unit The developer unit is not properly installed. Reinstall developer unit C so that the connector firmly connects. Developer Unit Replacement 2 Checking the wire The wire is not properly connected or is faulty. Reinsert the following wire connectors, and replace the wires when they have no continuity.• Drum/developer relay PWB - Feed image PWB• Feed image PWB - Engine PWB Electrical Diagram of PWBs 3 Replacing the drive gear The drive gear for developer unit C is damaged. (The spiral is not rotated.) Replace the drive gear for developer unit C. 4 Developer unit replacement Developer unit C (T/C sensor C) is faulty. Replace the developer unit C. Developer Unit Replacement 5 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 6 Replacing the drum/developer relay PWB The drum/developer relay PWB is faulty. Replace the drum/developer relay PWB. Drum/ Developer Relay PWB Replacement 7 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB. 8 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement

• Code: C7103
• Description: T/C sensor M error Object: Color models
• Causes: For the specified value of the initial toner stored in the EEPROM of the developer unit, the output value of the T/C sensor is out of the range between +100 (undetection toner) and -1000 (Coming off of the sensor connector). And that status was detected 3 times continuously.
• Remedy: 1 Reinstalling the developer unit The developer unit is not properly installed. Reinstall developer unit M so that the connector firmly connects. Developer Unit Replacement 2 Checking the wire The wire is not properly connected or is faulty. Reinsert the following wire connectors, and replace the wires when they have no continuity.• Drum/developer relay PWB - Feed image PWB• Feed image PWB - Engine PWB Electrical Diagram of PWBs 3 Replacing the drive gear The drive gear for developer unit M is damaged. (The spiral is not rotated.) Replace the drive gear for developer unit M. 4 Developer unit replacement Developer unit M (T/C sensor M) is faulty. Replace the developer unit M. Developer Unit Replacement 5 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 6 Replacing the drum/developer relay PWB The drum/developer relay PWB is faulty. Replace the drum/developer relay PWB. Drum/ Developer Relay PWB Replacement 7 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB. 8 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement