• Code: 7911
• Description: Developer unit K 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 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. Developer unit K and front PWB (YC9) Front PWB (YC2) and engine PWB (YC10)
  Defective developer unit K. Replace the developer unit K.

• Code: 7912
• Description: Developer unit C 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 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. Developer unit C and front PWB (YC13) Front PWB (YC2) and engine PWB (YC10)
  Defective developer unit C. Replace the developer unit C.

• 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.