1. Check the drill bit: the use of a dull or curved drill bit will make the motor overload surface work abnormally and reduce the working efficiency. Therefore, if such a situation is found, it should be dealt with and replaced immediately.

2. Inspection of the fastening screws of the electric drill body: check the fastening of the installation screws of the electric drill body before use. If the screws are found to be loose, they should be tightened immediately, otherwise the electric drill will malfunction.

3. Check the carbon brush: The carbon brush on the motor is a consumable. Once its abrasion exceeds the limit, the motor will malfunction. Therefore, the worn out carbon brush should be replaced immediately. In addition, the carbon brush must always be kept clean.

4. Inspection of protective grounding wire: The protective grounding wire is an important measure to protect personal safety. Therefore, Class I appliances (metal casing) should be checked frequently and the casing should be well grounded.