- FNS control board (FNSCB)
- SD control board (SDCB)
- 1st folding motor knife (M107)
- 1st folding knife home sensor (PS110)
- Check the half-fold/fold & staple/tri-fold section, and repair it if any abnormality.
- Check the connector connection and the wiring between FNSCB and SDCB, and repair it if any abnormality.
- Check the connector connection and the wiring between SDCB and motor/sensor, and repair it if any abnormality.
- Check the I/O drive of the motor of the coupling of the gear, and repair/replace it if any abnormality. (Wiring diagram: SD-510: 8-B)
- Check I/O and the operation of the sensor, and repair/replace it if any abnormality. (Wiring diagram: SD-510: 9-B)
- Replace PS110.
- Replace M107.
- Replace SDCB.
- Replace FNSCB.
