• Code: U1-01
• Description: FAX battery abnormality
  FAX backup SRAM battery voltage fall
• Causes: Battery life Battery circuit abnormality
• Remedy: Check that the battery voltage is about 2.5V or above. Check the battery circuit.

• Code: U1-02
• Description: RTC read abnormality (common with FAX, on ICU PWB)
  The value read from RTC on ICU PWB is [EE]h (abnormal).
• Causes: RTC circuit abnormality Battery voltage fall Battery circuit abnormality
• Remedy: Set the time again with key operation, and check that time advances properly. Check RTC circuit. Check that battery voltage is about 2.5V or above. Check battery circuit.

• Code: U2-00
• Description: EEPROM read/write error (ICU)
  EEPROM write error
• Causes: EEPROM trouble EEPROM is not initialized. ICU PWB EEPROM access circuit trouble
• Remedy: Check that EEPROM is properly inserted. Save the counter/adjustment values with the simulation. Use SIM16 to cancel U2 trouble. Replace the ICU PWB.

• Code: U2-11
• Description: Counter check sum error (ICU)
  Counter data area check sum error
• Causes: EEPROM trouble Control circuit trouble by noise ICU PWB EEPROM access circuit trouble
• Remedy: Check that EEPROM is properly inserted. Save the counter/adjustment values with the DIAG simulation. Use DIAG (SIM16) to cancel U2 trouble. Replace the ICU PWB.

• Code: U2-12
• Description: Adjustment value check sum error (ICU)
  Adjustment data area check sum error
• Causes: EEPROM trouble Control circuit trouble by noise ICU PWB EEPROM access circuit trouble
• Remedy: Check that EEPROM is properly inserted. Save the counter/adjustment values with the simulation. Use SIM16 to cancel U2 trouble. Replace the ICU PWB.

• Code: U2-22
• Description: SRAM memory check sum error (ICU)
  MFPC section SRAM memory check sum error
• Causes: SRAM trouble Control circuit runaway due to noises ICU PWB SRAM access circuit trouble
• Remedy: Initialize the communication management table registered in the SRAM and the FAX soft switch. Since the registered data are deleted, register the data again. Use SIM16 to cancel U2 trouble. Replace the ICU PWB.

• Code: U2-23
• Description: SRAM memory individual data check sum error (ICU)
  Check sum error for every data in the SRAM memory of the MFPC section (Communication management table, sender registration data, etc.)
• Causes: SRAM trouble Control circuit runaway due to noises ICU PWB SRAM access circuit trouble
• Remedy: Automatically initialize the data related to the check sum error by turning OFF/ ON the power. Since the registered data are deleted, register the data again. Use SIM16 to cancel U2 trouble. Replace the ICU PWB.

• Code: U2-50
• Description: HD section individual data check sum error (ICU)
  Check sum error for every individual data in HD of the MFPC section (Onetouch, Group, Program, etc.)
• Causes: HDD write/read error Control circuit runaway due to noises ICU PWB HD access circuit trouble
• Remedy: Automatically initialize the data related to the check sum error by turning OFF/ ON the power. Since the registered data are deleted, register the data again. Use SIM 16 to cancel the U2 trouble. Replace the HD PWB. Replace the ICU PWB.