• 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.
• Remedy: Developer unit K: 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Developer unit K and Front PWB (YC9) Front PWB (YC2) and Engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Developer unit K.
  Front PWB: Replace the front PWB.
  Engine PWB 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.

• 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.
• Remedy: Developer unit C: 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Developer unit C and Front PWB (YC13) Front PWB (YC2) and Engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Developer unit C.
  Front PWB: Replace the front PWB.
  Engine PWB: 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB5 times.

• 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.
• Remedy: Developer unit M: 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Developer unit M and Front PWB (YC11) Front PWB (YC2) and Engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Developer unit M.
  Front PWB: Replace the front PWB.
  Engine PWB 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.

• 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.
• Remedy: Developer unit Y: 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Developer unit Y and Front PWB (YC15) Front PWB (YC2) and Engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Developer unit Y.
  Front PWB: Replace the front PWB.
  Engine PWB: 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB5 times.

• Code: 7941
• Description: Laser scanner unit K EEPROM error
  [35 ppm/ 45 ppm/ 55 ppm model] Mismatch of reading data from two locations occurs 8 times successively. Mismatch between writing data and reading data occurs 8 times successively.
• Remedy: APC PWB K: 1. Confirm that the FCC wiring connector is not distorted and connect the FCC wiring all the way in. APC PWB K and LSU relay PWB (YC5) LSU relay PWB (YC2) and Engine PWB (YC11) 2. If the FCC wiring is disconnected, shorted or grounded, replace the FCC wiring. 3. Replace the laser scanner unit.
  LSU relay PWB: Replace the LSU relay PWB.
  Engine PWB: 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.

• Code: 7942
• Description: Laser scanner unit C EEPROM error
  [35 ppm/ 45 ppm/ 55 ppm model] Mismatch of reading data from two locations occurs 8 times successively. Mismatch between writing data and reading data occurs 8 times successively.
• Remedy: APC PWB C: 1. Confirm that the FCC wiring connector is not distorted and connect the FCC wiring all the way in. APC PWB C and LSU relay PWB (YC10) LSU relay PWB (YC2) and Engine PWB (YC11) 2. If the FCC wiring is disconnected, shorted or grounded, replace the FCC wiring. 3. Replace the laser scanner unit.
  LSU relay PWB: Replace the LSU relay PWB.
  Engine PWB: 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB5 times.

• Code: 7943
• Description: Laser scanner unit M EEPROM error
  [35 ppm/ 45 ppm/ 55 ppm model] Mismatch of reading data from two locations occurs 8 times successively. Mismatch between writing data and reading data occurs 8 times successively.
• Remedy: APC PWB M: 1. Confirm that the FCC wiring connector is not distorted and connect the FCC wiring all the way in. APC PWB M and LSU relay PWB (YC8) LSU relay PWB (YC2) and Engine PWB (YC11) 2. If the FCC wiring is disconnected, shorted or grounded, replace the FCC wiring. 3. Replace 1-5-43the laser scanner unit.
  LSU relay PWB: Replace the LSU relay PWB.
  Engine PWB: 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB5 times.

• Code: 7944
• Description: Laser scanner unit Y EEPROM error
  [35 ppm/ 45 ppm/ 55 ppm model] Mismatch of reading data from two locations occurs 8 times successively. Mismatch between writing data and reading data occurs 8 times successively.
• Remedy: APC PWB Y 1. Confirm that the FCC wiring connector is not distorted and connect the FCC wiring all the way in. APC PWB Y and LSU relay PWB (YC12) LSU relay PWB (YC2) and Engine PWB (YC11) 2. If the FCC wiring is disconnected, shorted or grounded, replace the FCC wiring. 3. Replace the laser scanner unit.
  LSU relay PWB: Replace the LSU relay PWB.
  Engine PWB: 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB