• Code: C7221
• Description: LSU thermistor broken The input sampling value of the LSU thermistor is at the reference value or more.
• Remedy: 1 Checking the connection FFC is not connected properly. Or it is faulty. Clean the FFC terminals of the following FFC and reconnect them. If the FFC terminal is deformed or broken, replace the FFC. . LSU (APC PWB) - Engine PWB Section 8 "PWBs" 2 LSU replacement The LSU (LSU thermistor) is faulty. Replace the LSU. Detaching and reattaching the LSU 3 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 4 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB

• Code: C7231
• Description: LSU thermistor short-circuited The input sampling value of the LSU thermistor is at the reference value or less.
• Remedy: 1 Checking the connection FFC is not connected properly. Or it is faulty. Clean the FFC terminals of the following FFC and reconnect them. If the FFC terminal is deformed or broken, replace the FFC. . LSU (APC PWB) - Engine PWB Section 8 "PWBs" 2 LSU replacement The LSU (LSU thermistor) is faulty. Replace the LSU. Detaching and reattaching the LSU 3 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Update 4 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Detaching and reattaching the Engine PWB

• Code: C7241
• Description: Belt thermistor broken The input sampling value of the belt thermistor is at the reference value or more.
• Remedy: 1 Reinstalling the primary transfer unit The primary transfer unit is not properly installed. Reinstall the primary transfer unit so that the connector firmly connects. Detaching and reattaching the Primary Transfer Unit 2 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 PWB - Transfer connect PWB . Transfer connect PWB - Feed image PWB Section 8 "PWBs" 3 Primary transfer unit replacement The primary transfer unit is faulty. Replace the primary transfer unit. Detaching and reattaching the Primary Transfer Unit 4 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version 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: C7251
• Description: Belt thermistor short-circuited The input sampling value of the belt thermistor is at the reference value or less.
• Remedy: 1 Reinstalling the primary transfer unit The primary transfer unit is not properly installed. Reinstall the primary transfer unit so that the connector firmly connects. Detaching and reattaching the Primary Transfer Unit 2 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 PWB - Transfer connect PWB . Transfer connect PWB - Feed image PWB Section 8 "PWBs" 3 Primary transfer unit replacement The primary transfer unit is faulty. Replace the primary transfer unit. Detaching and reattaching the Primary Transfer Unit 4 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version 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: C7301
• Description: Toner motor K error Toner supply motor drive stopped and waited for 0.1s when the pulse plate of the toner supply screw could not detect the pulse for 2s during the toner supply motor operation. Even if these operations repeated 3 times continuously, the pulse could not be detected.
• Remedy: 1 Checking the toner supply drive unit The toner supply screw is not rotated properly due to the excessive load. (The pulse plate is not rotated.) Check if the toner is not clogged inside the toner supply drive unit by rotating the toner supply screw manually. Then, clean the unit if necessary. 2 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 motor K - Feed image PWB Section 8 "PWBs" 3 Replacing the toner supply drive unit Toner supply drive unit (toner motor K or toner remaining sensor K) is faulty. Replace the toner supply drive unit. Detaching and reattaching the Toner Supply Drive Unit 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: C7302
• Description: Toner motor C error Toner supply motor drive stopped and waited for 0.1s when the pulse plate of the toner supply screw could not detect the pulse for 2s during the toner supply motor operation. Even if these operations repeated 3 times continuously, the pulse could not be detected.
• Remedy: 1 Checking the toner supply drive unit The toner supply screw is not rotated properly due to the excessive load. (The pulse plate is not rotated.) Check if the toner is not clogged inside the toner supply drive unit by rotating the toner supply screw manually. Then, clean the unit if necessary. 2 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 motor C - Feed image PWB Section 8 "PWBs" 3 Replacing the toner supply drive unit The toner supply drive unit (toner motor C or toner remaining amount sensor C) is faulty. Replace the toner supply drive unit. Detaching and reattaching the Toner Supply Drive Unit 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: C7303
• Description: Toner motor M error Toner supply motor drive stopped and waited for 0.1s when the pulse plate of the toner supply screw could not detect the pulse for 2s during the toner supply motor operation. Even if these operations repeated 3 times continuously, the pulse could not be detected.
• Remedy: 1 Checking the toner supply drive unit The toner supply screw is not rotated properly due to the excessive load. (The pulse plate is not rotated.) Check if the toner is not clogged inside the toner supply drive unit by rotating the toner supply screw manually. Then, clean the unit if necessary. 2 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 motor M - Feed image PWB Section 8 "PWBs" 3 Replacing the toner supply drive unit The toner supply drive unit (toner motor M or toner level sensor M) is faulty. Replace the toner supply drive unit. Detaching and reattaching the Toner Supply Drive Unit 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: C7304
• Description: Toner motor Y error Toner supply motor drive stopped and waited for 0.1s when the pulse plate of the toner supply screw could not detect the pulse for 2s during the toner supply motor operation. Even if these operations repeated 3 times continuously, the pulse could not be detected.
• Remedy: 1 Checking the toner supply drive unit The toner supply screw is not rotated properly due to the excessive load. (The pulse plate is not rotated.) Check if the toner is not clogged inside the toner supply drive unit by rotating the toner supply screw manually. Then, clean the unit if necessary. 2 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 motor Y - Feed image PWB Section 8 "PWBs" 3 Replacing the toner supply drive unit The toner supply drive unit (toner motor Y or toner level sensor Y) is faulty. Replace the toner supply drive unit. Detaching and reattaching the Toner Supply Drive Unit 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.