• Code: C8520
• Description: MB conveying motor error 2 Object: 4000-sheet finisher with the mail box
• Causes: The MB home position sensor does not turn off after passing 1s during the standby operation.
• Remedy: 1 Checking the MB conveying roller The MB conveying roller is not assembled properly. If the MB conveying roller is not rotated manually, repair the part that restricts the operation. 2 Checking the MB conveying roller drive components The MB conveying roller drive components are not properly attached, or they are faulty. Reattach the MB conveying roller drive components. 3 Replacing the MB conveying roller drive components The MB conveying roller drive components are faulty. Replace the MB conveying roller drive components. 4 Checking the wire The wire is not properly connected or is faulty. Reinsert the following wire connectors, and replace the wires if there is no continuity.• MB conveying motor - MB main PWB• MB home position sensor - MB main PWB Electrical Diagram of PWBs 5 Replacing the MB conveying motor The MB conveying motor is faulty. Replace the MB conveying motor if it does not operate properly when checking the operation at U240. U240 Execution 6 Checking the MB home position sensor The MB home position is not properly attached, or it is faulty. Reattach the MB home position sensor and execute U241 to check the operation. If it does not operate properly, replace the sensor. U241 Execution 7 Replacing the MB main PWB The MB main PWB is faulty. Replace the MB main PWB.

• Code: C8800
• Description: Main program error / Engine - DF communication error (DF)
• Causes: 1. The main program is faulty when turning the power on.2. The communication error between the engine and the DF was detected 10 times continuously.
• Remedy: 1 Resetting the main power The program does not start up 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 Firmware upgrade The firmware is not the latest version. Upgrade the DP firmware to the latest version. Firmware Upgrade 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.• DF main PWB - Engine PWB Electrical Diagram of PWBs 4 Replacing the DF main PWB The DF main PWB is faulty. Replace the DF main PWB. DF Main PWB Replacement 5 Firmware upgrade The firmware is not the latest version. Upgrade the engine firmware to the latest version Firmware Upgrade 6 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement

• Code: C8900
• Description: DF backup error
• Causes: The writing data and the reading data mismatch 3 times continuously.
• 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.• DF main PWB - Engine PWB Electrical Diagram of PWBs 2 Replacing the DF main PWB The DF main PWB is faulty. Replace the DF main PWB. DF Main PWB Replacement

• Code: C8930
• Description: BF unit backup error Object: 4000-sheet finisher
• Causes: The writing data and the reading data mismatch 3 times continuously.
• 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.• BF main PWB - DF main PWB Electrical Diagram of PWBs 2 Replacing the BF main PWB The BF main PWB is faulty. Replace the BF main PWB.

• Code: C9000
• Description: Main program error / DP communication error
• Causes: The document processor cannot be communicated.
• Remedy: 1 Firmware upgrade The firmware version between the main unit and the document processor mismatches. Upgrade the firmware for the main unit and the document processor to the latest version. Firmware Upgrade 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.• DP main PWB - Engine PWB Electrical Diagram of PWBs 3 Replacing the DP main PWB The DP main PWB is faulty. Replace the DP main PWB. DP Main PWB Replacement 4 Replacing the engine PWB The engine PWB is faulty. Replace the engine PWB. Engine PWB Replacement

• Code: C9040
• Description: DP lift motor ascend error Object: Dual scan DP and automatic duplex DP with the DP feed belt
• Causes: Turning on of the DP lift upper limit sensor could not be detected after passing 3000 pulses during the DP lift motor ascend drive. That status was continued 5 times or more.
• Remedy: 1 Checking the original lift plate The DP original lift plate is not properly attached. If the original lift plate is not shifted manually vertically, repair the part that restricts the operation. 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.• DP lift motor - DP main PWB• DP lift upper limit sensor - DP main PWB Electrical Diagram of PWBs 3 Replacing the DP lift motor The DP lift motor is faulty. Replace the DP lift motor if it does not operate properly when checking the operation at U243. U243 Execution 4 Checking the DP lift upper limit sensor The DP lift upper limit sensor is not properly attached, or it is faulty. Reattach the DP lift upper limit sensor and execute U241 to check the operation. If it does not operate properly, replace the sensor. U244 Execution 5 Replacing the DP main PWB The DP main PWB is faulty. Replace the DP main PWB. DP Main PWB Replacement

• Code: C9050
• Description: DP lift motor descend error Object: Dual scan DP and automatic duplex DP with the DP feed belt
• Causes: Turning on of the DP lift lower limit sensor could not be detected after passing 3000 pulses during the DP lift motor descend drive. (The recovery is 3 times.)
• Remedy: 1 Checking the original lift plate The DP original lift plate is not properly attached. If the original lift plate is not shifted manually vertically, repair the part that restricts the operation. 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.• DP lift motor - DP main PWB• DP lift upper limit sensor - DP main PWB Electrical Diagram of PWBs 3 Replacing the DP lift motor The DP lift motor is faulty. Replace the DP lift motor if it does not operate properly when checking the operation at U243. U243 Execution 4 Checking the DP lift lower limit sensor The DP lift lower limit sensor is not properly attached, or it is faulty. Reattach the DP lift lower limit sensor and execute U241 to check the operation. If it does not operate properly, replace the sensor. U244 Execution 5 Replacing the DP main PWB The DP main PWB is faulty. Replace the DP main PWB. DP Main PWB Replacement

• Code: C9060
• Description: DP EEPROM error
• Causes: The writing data and the reading data into the EEPROM mismatch.
• Remedy: 1 Checking the EEPROM The EEPROM is not properly installed. Reattach the EEPROM on the DP main PWB. 2 Replacing the DP main PWB The DP main PWB is faulty. Replace the DP main PWB. DP Main PWB Replacement 3 Replacing the EEPROM The EEPROM is faulty. Replace the EEPROM on the DP main PWB and execute U411. U411 Execution