• Code: U2 11
• Description: Counter check sum value stored in the EEPROM is abnormal.
• 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 Checksum error in counter data area

• Code: U2 12
• Description: Adjustment value check sum error (EEPROM)
• 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 Checksum error in adjustment value data area

• Code: U2 20
• Description: Machine speed code data error. The machine 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: 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.

• Code: U7 00
• Description: 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 Details 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: 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.

• Code: U9 81
• Description: Operation control PWB communication trouble (Parity). Communication trouble between MCU and the operation control PWB (Parity 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.