• Code: U1-01
• Description: FAX battery error
  The SRAM backup battery voltage on FAX PWB falls.
• Causes: The SRAM backup battery voltage on FAX PWB falls.
• Remedy: Check voltage of the SRAM back up battery. Replace the battery.

• Code: U1-02
• Description: PANEL LOW battery error
  The voltage of the panel clock function battery falls.
• Causes: The voltage of the panel clock function battery falls.
• Remedy: Check voltage of panel clock function battery. Replace the battery.

• Code: U2-04
• Description: EEPROM communication error
  MCU PWB EEPROM access circuit failure
• Causes: EEPROM defective ICU PWB EEPROM access circuit failure
• Remedy: Check that the EEPROM is properly set. Clear trouble with SIM 16. Replace the MCU PWB. Remarks EEPROM abnormality

• Code: U2-20
• Description: Machine speed code data error
  The machine (Boot) speed information is not identical to the model code speed information.
• Causes: EEPROM defective SIM operation error
• Remedy: Check that the machine set with SIM 26- 57 is identical to the model information. Remarks When the boot program speed code does not match with the body model information.

• Code: U2-40
• Description: CRUM chip communication error
  Error in MCU-CRUM chip communication
• Causes: CRUM chip failure Developing unit contact trouble MCU PWB failure
• Remedy: Replace the CRUM chip. Check installation of the developing unit. Clear the trouble with SIM 16. Replace the MCU PWB. Remarks CRUM communication error

• Code: U7-00
• Description: RIC communication trouble
  Error in communication with RIC Error in communication test after turning on the power or canceling SIM.
• Causes: Connector harness contact trouble or disconnection RIC control PWB trouble MCU PWB failure Malfunction by noises
• Remedy: Check the communication cable, connectors from the RIC box to the main body.

• Code: U9-00
• Description: MCU-OPE communication trouble
  Communication establishment error/ framing/parity/protocol error
• Causes: Operation control PWB connector disconnection Operation control PWB MCU PWB harness failure
• Remedy: Check the connectors and harness of the operation control PWB and MCU PWB. Check the grounding of the copier. Check ROM on the operation control PWB.

• Code: U9-80
• Description: Operation control PWB communication trouble (Protocol)
  Communication trouble between MCU and the operation control PWB (Protocol error)
• Causes: Operation control PWB connector disconnection Operation control PWB MCU PWB harness failure
• Remedy: Check the connectors and harness of the operation control PWB and MCU PWB. Check the grounding of the copier.