The electric screwdriver shall be powered on and operated for one minute. When it is operated, it shall be held by hand. The hand shall not feel any abnormal vibration obviously. Observe the reversing spark. The reversing spark shall not exceed 3/2 level. Generally, when viewed from the air inlet of the electric screwdriver, there shall be no obvious arc light on the surface of the commutator. There shall be no abnormal noise during operation.