• Code: E7-23
• Description: LSU laser detection error (Y)
• Causes: Reduced laser power, lighting error, laser diode trouble. Harness and connector trouble between the LD PWB and the LSU cnt PWB.
• Remedy: Use SIM61-1 to check the operation of the LSU. Check the PWB and connection of the harness in the LSU. Replace the LSU.

• Code: E7-28
• Description: LSU-PCU connection error
• Causes: Communication error between the CPU in the PCU PWB and the control ASIC. Improper connection of the communication connector between the PCU PWB and the LSU cnt PWB (interface PWB). Harness trouble between the PCU PWB and the LSU cnt PWB (interface PWB) PCU PWB or LSU cnt PWB (interface PWB) trouble
• Remedy: Check connection of the connector and the harness between the PCU PWB and the LSU cnt PWB (interface PWB). Replace the LSU cnt PWB. Replace the PCU PWB.

• Code: E7-29
• Description: LSU ASIC frequency error
• Causes: Oscillation abnormality of the external oscillator and the internal oscillating circuit used in the LSU ASIC. LSU ASIC abnormality on the LSU ASIC PWB.
• Remedy: Replace the LSU cnt PWB.

• Code: E7-50
• Description: Engine connection trouble
• Causes: A PWB, or firmware, or LSU which is not supported by the machine specifications is detected in the PCU PWB. PCU PWB trouble. LSU trouble.
• Remedy: Check the kind and the version of the firmware. Check the LSU, and replace it if necessary. Check the PCU PWB, and replace it if necessary.

• Code: E7-55
• Description: PWB information sum error (Engine detection)
• Causes: PCU EEPROM sum check error. PCU EEPROM trouble. PCU EEPROM contact trouble. Malfunction due to noises
• Remedy: Replace the PCU PWB. Replace the PCU EEPROM.

• Code: E7-60
• Description: Combination error between the MFP PWB and other PWB, firmware
• Causes: A PWB or firmware which is not supported by the machine specifications is detected in the MFP PWB. MFP PWB trouble. The PWB/firmware which is not supported by the machine specifications is connected.
• Remedy: Check the kind and the version of the firmware. Check the MFP PWB, and replace it if necessary.

• Code: E7-61
• Description: Combination error between the MFP PWB and the PCU PWB
• Causes: Combination error between the MFP PWB and the PCU PWB. MFP PWB trouble. PCU PWB trouble.
• Remedy: Check the combination between the MFP PWB and the PCU PWB. Replace the MFP PWB. Replace the PCU PWB.

• Code: E7-65
• Description: MFP EEPROM sum check error
• Causes: MFP PWB EEPROM device breakdown. Contact trouble of the MFP EEPROM device. Malfunction due to noises.
• Remedy: Replace the MFP PWB. Replace the MFP PWB EEPROM.