Code :

Code: U2-24
Description: SRAM memory user authentication counter check sum error
Causes: SRAM trouble. Control circuit malfunction due to noises. ICU PWB SRAM access circuit trouble.
Remedy: Recheck the check sum of the user counter with Sim.16 and save the normal sum value.

Code: U2-25
Description: Flash memory user authentication counter check sum error
Causes: Flash trouble. Control circuit malfunction due to noises. ICU PWB Flash access circuit malfunction.
Remedy: Recalculate the user counter check sum with Sim.16, and save the normal sum value.

Code: U2-30
Description: Production number data discrepancy (ICU-PCU). The production number saved in the PCU differs from that saved in the ICU
Causes: When replacing the PCU/ ICU PWB, the EEPROM is not changed.
Remedy: Check that the EEPROM is properly set. When replacing the PWB, check that the EEPROM before replacement is inserted to the PWB after replacement.

Code: U2-50
Description: HD section individual data check sum error (MFP). W-ICU PWB HD individual data check sum error. (One touch, group, program, etc.)
Causes: Read /write trouble from/ to HD. Control circuit malfunction due to line noise. W-ICU PWB HD access circuit trouble.
Remedy: Turn OFF / ON the power to initialize the data related to the content of check sum error. Since the registered content is deleted, register the deleted content again. Use Sim. 16 to cancel the U2 trouble. Replace the HD. Replace the MFPC, W-ICU PWB.

Code: U2-80
Description: EEPROM read / write error (SCU detection)
Causes: EEPROM trouble. Installation of non-initialized EEPROM. SCU PWB EEPROM access circuit trouble.
Remedy: Check that the EEPROM is properly set. To keep the counter data and the adjustment values, use the simulation to save the counter data and the adjustment values. (When there is a printer option, execute Sim.22-1 to save the counter data and the adjustment values.) Replace the SCU PWB. Use Sim. 16 to cancel the trouble.

Code: U2-81
Description: EEPROM check sum error (SCU detection)
Causes: EEPROM trouble. Control circuit malfunction due to line noise. SCU PWB EEPROM access circuit trouble.
Remedy: Check that the EEPROM is properly set. To keep the counter data and the adjustment values, use the simulation to save the counter data and the adjustment values. (When there is a printer option, execute Sim. 22-1 to save the counter data and the adjustment values.) Replace the SCN PWB. Use Sim. 16 to cancel the trouble.

Code: U2-90
Description: EEPROM read / write error (PCU detection)
Causes: EEPROM trouble. Installation of non-initialized EEPROM. PCU PWB EEPROM access circuit trouble.
Remedy: Check that the EEPROM is properly set. To keep the counter data and the adjustment values, use the simulation to save the counter data and the adjustment values. (When there is a printer option, execute Sim. 22-1 to save the counter data and the adjustment values.) Replace the PCU PWB. Use Sim. 16 to cancel the trouble.

Code: U2-91
Description: EEPROM check sum error (PCU detection)
Causes: EEPROM trouble. Control circuit malfunction due to noises. PCU PWB EEPROM access circuit trouble.
Remedy: Check that the EEPROM is properly set. To keep the counter data and the adjustment values, use the simulation to save the counter data and the adjustment values. (When there is a printer option, execute Sim. 22-1 to save the counter data and the adjustment values.) Replace the PCU PWB. Use Sim. 16 to cancel the trouble.