Description: Short-circuited external thermistor An abnormal value is detected in the input data to the outer temperature sensor.
Causes: Poor contact in the connector terminals. Defective engine PWB.
Remedy: Poor contact in the connector terminals. Check the connection of connector YC13 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective engine PWB. Replace the engine PWB and check for correct operation.
Code: C7901
Description: Drum BK EEPROM error Reading from or writing to EEPROM cannot be performed.
Causes: Poor contact in the connector terminals. Defective drum PWB BK.
Remedy: Poor contact in the connector terminals. Check the connection of connector YC18 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective drum PWB BK. Replace the drum unit BK.
Code: C7902
Description: Drum C EEPROM error Reading from or writing to EEPROM cannot be performed.
Causes: Poor contact in the connector terminals. Defective drum PWB C.
Remedy: Poor contact in the connector terminals. Check the connection of connector YC17 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective drum PWB C. Replace the drum unit C.
Code: C7903
Description: Drum M EEPROM error Reading from or writing to EEPROM cannot be performed.
Causes: Poor contact in the connector terminals. Defective drum PWB M.
Remedy: Poor contact in the connector terminals. Check the connection of connector YC17 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective drum PWB M. Replace the drum unit M.
Code: C7904
Description: Drum Y EEPROM error Reading from or writing to EEPROM cannot be performed.
Causes: Poor contact in the connector terminals. Defective drum PWB Y.
Remedy: Poor contact in the connector terminals. Check the connection of connector YC18 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective drum PWB Y. Replace the drum unit Y.
Code: C7911
Description: Developing unit BK EEPROM error Reading from or writing to EEPROM cannot be performed.
Causes: Poor contact in the connector terminals. Defective developing PWB BK.
Remedy: Poor contact in the connector terminals. Check the connection of connector YC18 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective developing PWB BK. Replace the developing unit BK.
Code: C7912
Description: Developing unit C EEPROM error Reading from or writing to EEPROM cannot be performed.
Causes: Poor contact in the connector terminals. Defective developing PWB C.
Remedy: Poor contact in the connector terminals. Check the connection of connector YC17 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective developing PWB C. Replace the developing unit C.
Code: C7913
Description: Developing unit M EEPROM error Reading from or writing to EEPROM cannot be performed.
Causes: Poor contact in the connector terminals. Defective developing PWB M.
Remedy: Poor contact in the connector terminals. Check the connection of connector YC17 on the engine PWB and the continuity across the connector terminals. Repair or replace if necessary. Defective developing PWB M. Replace the developing unit M.