1. Unplug the power cord. Safety first.
2. Remove the plastic sheath and take the Phillips screwdriver counterclockwise to unlock the two screws.
3. Take a word screwdriver and solve the pair of left and right carbon brush counterclockwise. Use a needle-nosed pliers to remove the carbon brush, carefully remember the installation position of the carbon brush, and restore it smoothly.
4. Use a brush to clean the dust from the carbon brush. Gently spray when there is an air spray gun.
5. The outer casing should be slightly opened.
6. Use your fingers to turn the motor shaft to see if there is any sound from the machine and metal friction.
7. Make sure that there is no dust, use the universal needle oil, drop a little into the seam on the ring, and screw the shaft down to ensure the oil is eaten.
8. Wipe off the remaining oil, otherwise it will be dusted in the future.
9. Follow the steps above to restore the device.
10. After tightening the screws, first screw them with your fingers to see if they are not smooth. If the carbon brushes are installed well, make sure there are no abnormalities.
11. Plug in and power on, until the boot sound is normal!