• Code: 7800
• Description: Broken outer temperature sensor 1 wire The device did not respond for more than 5 ms during reading, in 5 times.
• Remedy: Outer temperature sensor 1 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Outer temperature sensor 1 and Front PWB (YC16) Front PWB (YC2) and Engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Outer temperature sensor 1.
  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: 7901
• Description: Drum 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: DR PWB-K 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. DR PWB-K and Front PWB (YC7) Front PWB (YC2) and Engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Drum 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: 7902
• Description: Drum 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: DR PWB- C 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. DR PWB- C and Front PWB (YC12) Front PWB (YC2) and Engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Drum 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 PWB.

• Code: 7903
• Description: Drum 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: DR PWB- M 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. DR PWB- M and Front PWB (YC10) Front PWB (YC2) and Engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Drum 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: 7904
• Description: Drum 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: DRPWB- Y 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. DRPWB- Y and Front PWB (YC14) Front PWB (YC2) and Engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Drum 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 PWB.

• 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 PWB.

• 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.