What was found
(CAN) ON ACTIVATION OF LANDING LIGHTS, CIRCUIT BREAKER TRIPPED. CIRCUIT BREAKER WAS RESET AND LIGHTS ACTIVATED AGAIN. CIRCUIT BREAKER AGAIN TRIPPED. ON INVESTIGATION OF DEFECT, LT LANDING LIGHT RELAY FOUND TO BE SHORTED OUT BECAUSE OF CONTACT FROM SCREW HOLDING ACCESS PANEL ON LT LOWER SIDE OF INSTRUMENT PANEL. SCREW LENGTH FOUND TO BE IMPROPER LENGTH AND PENETRATED THROUGH NUT PLATE AND THROUGH SIDE OF RELAY CAUSING IT TO SHORT OUT AND TRIP CIRCUIT BREAKER. PROPER SCREW LENGTH SHOULD BE USED SO THAT THIS PROBLEM DOES NOT REOCCUR.