• Code: C7320
• Description: Toner container detection connector error Disconnection of the toner container detection connector was detected when closing the toner container cover.
• Remedy: 1 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Container drive unit (RFID PWB) - Feed image PWB Section 8 "PWBs" 2 Checking the container drive unit The connector is not connected properly, or the wire is faulty. If the connector of the wire inside the container drive unit disconnects, reconnect it. If not repaired, replace the container drive unit. 3 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 4 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB.

• Code: C7420
• Description: Uninstalled primary transfer unit 1. Unit identification code does not match. 2. Unit for the other model is installed.
• Remedy: 1 Primary transfer unit replacement The primary transfer unit for other models is installed. Install the primary transfer unit for the applicable models. Detaching and reattaching the Primary Transfer Unit 2 Reinstalling the primary transfer unit The connector of the primary transfer unit is not firmly connected. Reinstall the primary transfer unit so that the connector firmly connects. Detaching and reattaching the Primary Transfer Unit 3 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Transfer connect PWB - Feed image PWB Section 8 "PWBs" 4 Firmware upgrade The firmware is faulty. Reinstall the engine firmware. Firmware Update 5 Replacing the transfer connection PWB The transfer connection PWB is faulty. Replace the transfer connection PWB. 6 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB.

• Code: C7470
• Description: Toner sucking fan motor error The lock-up was detected for 20s continuously when driving the fan motor.
• Remedy: 1 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Toner absorption fan motor - Feed image PWB Section 8 "PWBs" 2 Checking the toner sucking fan motor The fan motor does not rotate properly since it is dirty. Clean the toner sucking fan motor and check if the fan is rotated manually. Then, reattach it. Fan Motors Attachable Direction 3 Replacing the toner sucking fan motor The toner sucking fan motor is faulty. Execute U037 [Toner] to check the operation. If the toner absorption fan motor does not properly operate, replace it. Fan Motors Attachable Direction 4 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 5 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB.

• Code: C7480
• Description: Power source fan motor error The lock-up was detected for 20s continuously when driving the fan motor.
• Remedy: 1 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Power source fan motor - Engine PWB Section 8 "PWBs" 2 Checking the power source fan motor The fan motor does not rotate properly since it is dirty. Clean the power source fan motor and check if the fan is rotated manually. Then, reattach it. Fan Motors Attachable Direction 3 Replacing the power source fan motor The power source fan motor is faulty. Replace the power source fan motor if it does not operate properly when executing U037 [LVU]. Fan Motors Attachable Direction 4 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 5 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB

• Code: C7490
• Description: Eject fan motor error The lock-up was detected for 20s continuously when driving the fan motor.
• Remedy: 1 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Exit fan motor (Fuser drive unit) - Feed drive PWB Section 8 "PWBs" 2 Checking the eject fan motor The fan motor does not rotate properly since it is dirty. Clean the eject fan motor and check if the fan is rotated manually. Then, reattach it. Fan Motors Attachable Direction 3 Replacing the eject fan motor The eject fan motor is faulty. If the exit fan motor does not operate properly when executing U037 [Exit Cooling], replace it. Fan Motors Attachable Direction 4 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 5 Replacing the feed image PWB The feed image PWB is faulty. Replace the feed image PWB.

• Code: C7601
• Description: Front ID sensor error Dark potential error: Sensor output value (FrontDarkP, FrontDarkS) is less than 0.15V or bigger than 0.80V. Bright potential error: FrontBrightS is less than FrontDarkS or FrontBrightP is less than FrontDarkP+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. Execute U033 [ID Sensor]. If the ID sensor shutter does not operate properly, reattach the cleaning solenoid. Maintenanc e Mode List 3 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Front ID sensor - Feed drive PWB . Cleaning solenoid - Feed drive PWB . Feed drive PWB - Engine PWB Section 8 "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 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). Maintenanc e Mode List 7 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 8 Replacing the feed drive PWB The feed drive PWB is faulty. Replace the feed drive PWB. 9 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB

• Code: C7602
• Description: Rear ID sensor error Dark potential error: Sensor output value (RearDarkP, RearDarkS) is less than 0.15V or bigger than 0.80V. Bright potential error: RearBrightS is less than RearDarkS or RearBrightP is less than RearDarkP+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. Execute U033 [ID Sensor]. If the ID sensor shutter does not operate properly, reattach the cleaning solenoid. Maintenanc e Mode List 3 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Rear ID sensor - Feed drive PWB . Cleaning solenoid - Feed drive PWB . Feed drive PWB - Engine PWB Section 8 "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 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 rear ID sensor if it was not fluctuated (uncalibrated). Maintenanc e Mode List 7 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 8 Replacing the feed drive PWB The feed drive PWB is faulty. Replace the feed drive PWB. 9 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB

• Code: C7611
• Description: Bias calibration read value error (Black) 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 (In case if the printout is light) Checking the developer unit The developing roller does not contact with the drum. Switch the lock lever up and down and return the developer roller to the setting position. If the developer roller does not return due to the breakage of the lock lever or the failure of the developer roller pressure wire, replace the developer unit. Detaching and reattaching the Developer Unit 3 4 (In case if the printout is light) Cleaning / replacing the LSU. The laser does not output properly from the LSU. Or, LSU dustproof glass is dirty. Clean the LSU. If not repaired, replace it. Detaching and reattaching the LSU 5 (In case if the printout is light) Improving the condensation of the drum surface Condensation on the drum surface Execute the drum refresh. And next, set [On] at U339 [Drum heater] to turn on the drum heater. Adjustment/ Maintenanc e Menu (Operation Guide - Section 10) Maintenanc e Mode List 6 Cleaning the ID sensor The ID sensor is dirty. Clean the surface of the front and rear ID sensors. 7 Executing Calibration The last calibration failed. Execute U464 [Calib]. Maintenanc e Mode List 8 Checking the ID sensor shutter The ID sensor shutter does not operate properly. Execute U033 [ID Sensor]. If the ID sensor shutter does not operate properly, reattach the cleaning solenoid. Maintenanc e Mode List 9 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. Detaching and reattaching the Primary Transfer Unit 10 Checking the ID sensor The ID sensor is not properly attached, or the connector is not properly connected. Reattach the front and rear ID sensors and reconnect the connectors. 11 (When the image is too light) Checking the main high voltage PWB / transfer high voltage PWB Proper current does not flow as the main high voltage PWB or the contact point of the transfer high voltage PWB is faulty. Reattach the main high voltage PWB and the transfer high voltage PWB. 12 (When the image is too light) Checking the drum unit / developer unit / LSU The parts for the drum unit, developer unit and LSU is dirty or worn out. In case if the image is too light, clean the drum unit, developer unit and the LSU. Or, replace them. Maintenanc e parts replacemen t procedures 13 Firmware upgrade The firmware is not the latest version. Upgrade the firmware to the latest version. Firmware Update 14 Checking the connection The connector is not connected properly, or the wire is faulty. Clean the terminal of the following wire connectors and reconnect the connectors. If there is no continuity, replace the wire. . Front ID sensor and Rear ID sensor - Feed drive PWB . Feed drive PWB - Engine PWB Section 8 "PWBs" 15 Replacing the feed drive PWB The feed drive PWB is faulty. Replace the feed drive PWB. 16 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB