1. Find out the reason why the traffic light at the position of the circuit breaker is not on: (1) First check whether the filament of the indicator light bulb is broken, loose or in poor contact. (2) Check whether the contacts of the working circuit are in good condition. (3) Check whether the lamps and lanterns are in good contact with the additional resistance. (4) Check whether the opening and closing contactor coil is damaged, and whether the current coil of the anti-drop relay is damaged. 2. Precautions when searching: (1) You must search by two people. (2) The anode and cathode cannot be grounded or short-circuited. (3) In addition to the need to replace the light bulb, other abnormal handling should be reported to the dispatcher on duty and handled by relevant professional teams.