• Code: 7913
• Description: Developer unit M EEPROM error
  No response is issued from the device in reading/writing for 5 ms or more and this problem is repeated five times successively. Mismatch of reading data from two locations occurs 8 times successively. Mismatch between writing data and reading data occurs 8 times successively.
• Causes: Defective connector cable or poor contact in the connector.
  Defective developer unit M.
• Remedy: Defective connector cable or poor contact in the connector. Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. Developer unit M and front PWB (YC11) Front PWB (YC2) and engine PWB (YC10)
  Defective developer unit M. Replace the developer unit M.

• Code: 7914
• Description: Developer unit Y EEPROM error
  No response is issued from the device in reading/writing for 5 ms or more and this problem is repeated five times successively. Mismatch of reading data from two locations occurs 8 times successively. Mismatch between writing data and reading data occurs 8 times successively.
• Causes: Defective connector cable or poor contact in the connector.
  Defective developer unit Y.
• Remedy: Defective connector cable or poor contact in the connector. Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. Developer unit Y and front PWB (YC15) Front PWB (YC2) and engine PWB (YC10)
  Defective developer unit Y. Replace the developer unit Y.

• Code: 7941
• Description: Laser scanner unit K EEPROM error
  Mismatch of reading data from two locations occurs 8 times successively. Mismatch between writing data and reading data occurs 8 times successively.
• Causes: Defective connector cable or poor contact in the connector.
  Defective APC PWB K.
• Remedy: Defective connector cable or poor contact in the connector. Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. APC PWB K and LSU relay PWB (YC5) LSU relay PWB (YC2) and engine PWB (YC11)
  Defective APC PWB K. Replace the laser scanner unit.

• Code: 7942
• Description: Laser scanner unit C EEPROM error
  Mismatch of reading data from two locations occurs 8 times successively. Mismatch between writing data and reading data occurs 8 times successively.
• Causes: Defective connector cable or poor contact in the connector.
  Defective APC PWB C.
• Remedy: Defective connector cable or poor contact in the connector. Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. APC PWB C and LSU relay PWB (YC10) LSU relay PWB (YC2) and engine PWB (YC11)
  Defective APC PWB C. Replace the laser scanner unit.

• Code: 7943
• Description: Laser scanner unit M EEPROM error
  Mismatch of reading data from two locations occurs 8 times successively. Mismatch between writing data and reading data occurs 8 times successively.
• Causes: Defective connector cable or poor contact in the connector.
  Defective APC PWB M.
• Remedy: Defective connector cable or poor contact in the connector. Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. APC PWB M and LSU relay PWB (YC8) LSU relay PWB (YC2) and engine PWB (YC11)
  Defective APC PWB M. Replace the laser scanner unit.

• Code: 7944
• Description: Laser scanner unit Y EEPROM error
  Mismatch of reading data from two locations occurs 8 times successively. Mismatch between writing data and reading data occurs 8 times successively.
• Causes: Defective connector cable or poor contact in the connector.
  Defective APC PWB Y.
• Remedy: Defective connector cable or poor contact in the connector. Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. APC PWB Y and LSU relay PWB (YC12) LSU relay PWB (YC2) and engine PWB (YC11)
  Defective APC PWB Y. Replace the laser scanner unit.

• Code: 8010
• Description: Punch motor error 1
  When the punch motor is driven, punch home position sensor does not turn on within 200 ms.
• Causes: Defective connector cable or poor contact in the connector (4000-sheet finisher).
  Defective connector cable or poor contact in the connector (1000-sheet finisher).
  Defective punch home position sensor.
  Defective punch motor.
  Defective PWB.
• Remedy: Defective connector cable or poor contact in the connector (4000-sheet finisher). Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. Punch motor and punch PWB (YC4) Punch home position sensor and punch PWB (YC8) Punch PWB (YC1) and DF main PWB (YC7)
  Defective connector cable or poor contact in the connector (1000-sheet finisher). Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. Punch motor and punch PWB (YC4) Punch home position sensor and punch PWB (YC8) Punch PWB (YC1) and DF main PWB (YC8)
  Defective punch home position sensor. Replace the punch home position sensor.
  Defective punch motor. Replace the punch motor.
  Defective PWB. Replace the punch PWB or DF main PWB and check for correct operation.

• Code: 8020
• Description: Punch motor error 2
  Home position is not obtained in 3 seconds after home position is initialized or in standby.
• Causes: Defective connector cable or poor contact in the connector (4000-sheet finisher).
  Defective connector cable or poor contact in the connector (1000-sheet finisher).
  Defective punch motor.
  Defective PWB.
• Remedy: Defective connector cable or poor contact in the connector (4000-sheet finisher). Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. Punch motor and punch PWB (YC4) Punch PWB (YC1) and DF main PWB (YC7)
  Defective connector cable or poor contact in the connector (1000-sheet finisher). Reinsert the connector. Also check for continuity within the connector cable. If none, replace the cable. Punch motor and punch PWB (YC4) Punch PWB (YC1) and DF main PWB (YC8)
  Defective punch motor. Replace the punch motor.
  Defective PWB. Replace the punch PWB or DF main PWB and check for correct operation.