• Code: C7601
• Description: Front ID sensor error
• Causes: • Dark potential error: The sensor output value (FrontDarkP and FrontDardS) is less than 0.15V, or more than 0.80V.• Light potential error: FrontBrightS is less than FrontDarkS, or FrontBrightP is less than Front- DarkP+0.5V.
• Remedy: 1 Cleaning the front ID sensor The front ID sensor is dirty. Clean the front ID sensor surface. 2 Checking the ID sensor shutter The ID sensor shutter does not operate properly. If the ID sensor shutter does not operate properly when executing U033 [ID Sensor], reattach the cleaning solenoid. U033 Execution 3 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.• Cleaning solenoid - Feed drive PWB• Feed drive PWB - Engine PWB Electrical Diagram of PWBs 4 Replacing the cleaning solenoid The cleaning solenoid is faulty. Replace the cleaning solenoid. 5 Checking the front ID sensor The front ID sensor is not properly attached. Reattach the front ID sensor. 6 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.• Front ID sensor - Feed drive PWB Electrical Diagram of PWBs 7 Replacing the front D sensor The front ID sensor is faulty. Check if the value of U465 [T7 CTD] is fluctuated before and after Calibration, and replace the front ID sensor if it was not fluctuated (uncalibrated). U465 Execution 8 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 9 Replacing the feed drive PWB The feed drive PWB is faulty. Replace the feed drive PWB. 10 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement

• Code: C7602
• Description: Rear ID sensor error
• Causes: • Dark potential error: The sensor output value (FrontDarkP and FrontDardS) is less than 0.15V, or more than 0.80V.• Light potential error: FrontBrightS is less than FrontDarkS, or FrontBrightP is less than Front- DarkP+0.5V
• Remedy: 1 Cleaning the rear ID sensor The rear ID sensor is dirty. Clean the rear ID sensor surface. 2 Checking the ID sensor shutter The ID sensor shutter does not operate properly. If the ID sensor shutter does not operate properly when executing U033 [ID Sensor], reattach the cleaning solenoid. U033 Execution 3 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.• Cleaning solenoid - Feed drive PWB• Feed drive PWB - Engine PWB Electrical Diagram of PWBs 4 Replacing the cleaning solenoid The cleaning solenoid is faulty. Replace the cleaning solenoid. 5 Checking the rear ID sensor The rear ID sensor is not properly attached. Reattach the rear ID sensor. 6 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.• Rear ID sensor - Feed drive PWB Electrical Diagram of PWBs 7 Replacing the rear ID sensor The rear ID sensor is faulty. Check if the value of U465 [T7 CTD] is fluctuated before and after Calibration, and replace the front ID sensor if it was not fluctuated (uncalibrated). U465 Execution 8 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 9 Replacing the feed drive PWB The feed drive PWB is faulty. Replace the feed drive PWB. 10 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement

• Code: C7611
• Description: Bias calibration read value error (Black)
• Causes: The ID sensors cannot properly read the patch density on the primary transfer belt when executing Calibration or Color Registration.
• Remedy: 1 Resetting the main power The ID sensor does not operate properly. Turn the power switch and the main power switch off . After 5s passes, turn the main power switch and the power switch on. 2 Cleaning the ID sensor The ID sensor is dirty. Clean the ID sensor surface. 3 Executing Calibration The last calibration failed. Execute U464 [Calib]. U464 Execution 4 Checking the ID sensor shutter The ID sensor shutter does not operate properly. If the ID sensor shutter does not operate properly when executing U033 [ID Sensor], reattach the cleaning solenoid. U033 Execution 5 Checking the primary transfer unit The primary transfer belt surface is dirty. Clean the surface of the primary transfer belt, or replace the primary transfer unit. Primary Transfer Unit Replacement 6 Checking the ID sensor The ID sensor is not properly attached, or the wire is not properly connected. Reattach the ID sensor and reconnect the wire. 7 (When the image is too light) Checking the main high-voltage PWB and the transfer high-voltage PWB The contacts of the main high-voltage PWB and the transfer high-voltage PWB are faulty, and so, the proper voltage is not applied. Reinstall the main high-voltage PWB and the transfer high-voltage PWB. Main Highvoltage PWB / Transfer High-voltage PWB Replacement 8 (When the print is too light) Cleaning or replacing the drum unit / developer unit / LSU The parts in the drum unit, developer unit or the LSU are dirty or worn down. Clean or replace the drum unit, developer unit and the LSU if the output image is too light. Drum Unit / Developer Unit / LSU Replacement 9 Firmware upgrade The firmware is not the latest version. Upgrade the firmware to the latest version. Firmware Upgrade 10 Checking the feed drive PWB The feed drive PWB is faulty. Reconnect the connectors on the feed drive PWB wires. Then, fix or replace the wires if they are pinched by the other part or if they have any damage. When the issue is not resolved, replace the feed drive PWB. Electrical Diagram of PWBs 11 Checking the engine PWB The engine PWB is faulty. Reconnect the connectors on the engine PWB. Then, fix or replace the wires if they are pinched by the other part or if they have any damage. When the issue is not resolved after that, replace the engine PWB. Engine PWB Replacement

• Code: C7612
• Description: Bias calibration read value error (Cyan) Object: Color models
• Causes: The ID sensors cannot properly read the patch density on the primary transfer belt when executing Calibration or Color Registration.
• Remedy: 1 Resetting the main power The ID sensor does not operate properly. Turn the power switch and the main power switch off . After 5s passes, turn the main power switch and the power switch on. 2 Cleaning the ID sensor The ID sensor is dirty. Clean the ID sensor surface. 3 Executing Calibration The last calibration failed. Execute U464 [Calib]. U464 Execution 4 Checking the ID sensor shutter The ID sensor shutter does not operate properly. If the ID sensor shutter does not operate properly when executing U033 [ID Sensor], reattach the cleaning solenoid. U033 Execution 5 Checking the primary transfer unit The primary transfer belt surface is dirty. Clean the surface of the primary transfer belt, or replace the primary transfer unit. Primary Transfer Unit Replacement 6 Checking the ID sensor The ID sensor is not properly attached, or the wire is not properly connected. Reattach the ID sensor and reconnect the wire. 7 (When the image is too light) Checking the main high-voltage PWB and the transfer high-voltage PWB The contacts of the main high-voltage PWB and the transfer high-voltage PWB are faulty, and so, the proper voltage is not applied. Reinstall the main high-voltage PWB and the transfer high-voltage PWB. Main Highvoltage PWB / Transfer High-voltage PWB Replacement 8 (When the print is too light) Cleaning or replacing the drum unit / developer unit / LSU The parts in the drum unit, developer unit or the LSU are dirty or worn down. Clean or replace the drum unit, developer unit and the LSU if the output image is too light. Drum Unit / Developer Unit / LSU Replacement 9 Firmware upgrade The firmware is not the latest version. Upgrade the firmware to the latest version. Firmware Upgrade 10 Checking the feed drive PWB The feed drive PWB is faulty. Reconnect the connectors on the feed drive PWB wires. Then, fix or replace the wires if they are pinched by the other part or if they have any damage. When the issue is not resolved, replace the feed drive PWB. Electrical Diagram of PWBs 11 Checking the engine PWB The engine PWB is faulty. Reconnect the connectors on the engine PWB. Then, fix or replace the wires if they are pinched by the other part or if they have any damage. When the issue is not resolved after that, replace the engine PWB. Engine PWB Replacement

• Code: C7613
• Description: Bias calibration read value error (Magenta) Object: Color models
• Causes: The ID sensors cannot properly read the patch density on the primary transfer belt when executing Calibration or Color Registration.
• Remedy: 1 Resetting the main power The ID sensor does not operate properly. Turn the power switch and the main power switch off . After 5s passes, turn the main power switch and the power switch on. 2 Cleaning the ID sensor The ID sensor is dirty. Clean the ID sensor surface. 3 Executing Calibration The last calibration failed. Execute U464 [Calib]. U464 Execution 4 Checking the ID sensor shutter The ID sensor shutter does not operate properly. If the ID sensor shutter does not operate properly when executing U033 [ID Sensor], reattach the cleaning solenoid. U033 Execution 5 Checking the primary transfer unit The primary transfer belt surface is dirty. Clean the surface of the primary transfer belt, or replace the primary transfer unit. Primary Transfer Unit Replacement 6 Checking the ID sensor The ID sensor is not properly attached, or the wire is not properly connected. Reattach the ID sensor and reconnect the wire. 7 (When the image is too light) Checking the main high-voltage PWB and the transfer high-voltage PWB The contacts of the main high-voltage PWB and the transfer high-voltage PWB are faulty, and so, the proper voltage is not applied. Reinstall the main high-voltage PWB and the transfer high-voltage PWB. Main Highvoltage PWB / Transfer High-voltage PWB Replacement 8 (When the print is too light) Cleaning or replacing the drum unit / developer unit / LSU The parts in the drum unit, developer unit or the LSU are dirty or worn down. Clean or replace the drum unit, developer unit and the LSU if the output image is too light. Drum Unit / Developer Unit / LSU Replacement 9 Firmware upgrade The firmware is not the latest version. Upgrade the firmware to the latest version. Firmware Upgrade 10 Checking the feed drive PWB The feed drive PWB is faulty. Reconnect the connectors on the feed drive PWB wires. Then, fix or replace the wires if they are pinched by the other part or if they have any damage. When the issue is not resolved, replace the feed drive PWB. Electrical Diagram of PWBs 11 Checking the engine PWB The engine PWB is faulty. Reconnect the connectors on the engine PWB. Then, fix or replace the wires if they are pinched by the other part or if they have any damage. When the issue is not resolved after that, replace the engine PWB. Engine PWB Replacement

• Code: C7614
• Description: Bias calibration read value error (Yellow) Object: Color models
• Causes: The ID sensors cannot properly read the patch density on the primary transfer belt when executing Calibration or Color Registration
• Remedy: 1 Resetting the main power The ID sensor does not operate properly. Turn the power switch and the main power switch off . After 5s passes, turn the main power switch and the power switch on. 2 Cleaning the ID sensor The ID sensor is dirty. Clean the ID sensor surface. 3 Executing Calibration The last calibration failed. Execute U464 [Calib]. U464 Execution 4 Checking the ID sensor shutter The ID sensor shutter does not operate properly. If the ID sensor shutter does not operate properly when executing U033 [ID Sensor], reattach the cleaning solenoid. U033 Execution 5 Checking the primary transfer unit The primary transfer belt surface is dirty. Clean the surface of the primary transfer belt, or replace the primary transfer unit. Primary Transfer Unit Replacement 6 Checking the ID sensor The ID sensor is not properly attached, or the wire is not properly connected. Reattach the ID sensor and reconnect the wire. 7 (When the image is too light) Checking the main high-voltage PWB and the transfer high-voltage PWB The contacts of the main high-voltage PWB and the transfer high-voltage PWB are faulty, and so, the proper voltage is not applied. Reinstall the main high-voltage PWB and the transfer high-voltage PWB. Main Highvoltage PWB / Transfer High-voltage PWB Replacement 8 (When the print is too light) Cleaning or replacing the drum unit / developer unit / LSU The parts in the drum unit, developer unit or the LSU are dirty or worn down. Clean or replace the drum unit, developer unit and the LSU if the output image is too light. Drum Unit / Developer Unit / LSU Replacement 9 Firmware upgrade The firmware is not the latest version. Upgrade the firmware to the latest version. Firmware Upgrade 10 Checking the feed drive PWB The feed drive PWB is faulty. Reconnect the connectors on the feed drive PWB wires. Then, fix or replace the wires if they are pinched by the other part or if they have any damage. When the issue is not resolved, replace the feed drive PWB. Electrical Diagram of PWBs 11 Checking the engine PWB The engine PWB is faulty. Reconnect the connectors on the engine PWB. Then, fix or replace the wires if they are pinched by the other part or if they have any damage. When the issue is not resolved after that, replace the engine PWB. Engine PWB Replacement

• Code: C7620
• Description: Automatic color registration error Object: Color models
• Causes: 1. The patch print position on the primary transfer belt is not within the readable area by the ID sensor.2. The primary transfer belt surface is dirty, or the patch print density is too light.
• Remedy: 1 Resetting the main power The ID sensor does not operate properly. Turn the power switch and the main power switch off . After 5s passes, turn the main power switch and the power switch on. 2 Cleaning the ID sensor The ID sensor is dirty. Clean the ID sensor surface. 3 Executing Calibration The last calibration failed. Execute U464 [Calib]. U464 Execution 4 Checking the ID sensor shutter The ID sensor shutter does not operate properly. If the ID sensor shutter does not operate properly when executing U033 [ID Sensor], reattach the cleaning solenoid. U033 Execution 5 Checking the primary transfer unit The primary transfer belt surface is dirty. Clean the surface of the primary transfer belt, or replace the primary transfer unit. Primary Transfer Unit Replacement 6 (When the image is too light) Checking the main high-voltage PWB and the transfer high-voltage PWB The contacts of the main high-voltage PWB and the transfer high-voltage PWB are faulty, and so, the proper voltage is not applied. Reinstall the main high-voltage PWB and the transfer high-voltage PWB. Main Highvoltage PWB / Transfer High-voltage PWB Replacement 7 (When the print is too light) Cleaning or replacing the drum unit / developer unit / LSU The parts in the drum unit, developer unit or the LSU are dirty or worn down. Clean or replace the drum unit, developer unit and the LSU if the output image is too light. Drum Unit / Developer Unit / LSU Replacement 8 (When color registration is shifted) Reinstalling or replacing the LSU and the drum unit The LSU or the drum unit is not installed in the correct position, or the LSU is faulty. Reinstall the LSU and the drum unit to the correct positions when the color registration is shifted. If the issue is not resolved, replace the LSU. 9 Checking the ID sensor The ID sensor is not properly attached, or the wire is not properly connected. Reattach the ID sensor and reconnect the wire. 10 Firmware upgrade The firmware is not the latest version. Upgrade the firmware to the latest version. Firmware Upgrade 11 Checking the feed drive PWB The feed drive PWB is faulty. Reconnect the connectors on the feed drive PWB wires. Then, fix or replace the wires if they are pinched by the other part or if they have any damage. When the issue is not resolved, replace the feed drive PWB. Electrical Diagram of PWBs 12 Checking the engine PWB The engine PWB is faulty. Reconnect the connectors on the engine PWB. Then, fix or replace the wires if they are pinched by the other part or if they have any damage. When the issue is not resolved after that, replace the engine PWB. Engine PWB Replacement

• Code: C7800
• Description: Outer thermistor broken
• Causes: The input sampling value of the temperature/humidity sensor (outer thermistor) is at the reference value or more
• Remedy: 1 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.• Temperature/humidity sensor - Engine PWB Electrical Diagram of PWBs 2 Replacing the temperature/ humidity sensor The temperature/humidity sensor is faulty. Replace the temperature/ humidity sensor. 3 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 4 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement