What was found
DURING APPROACH, PILOT SELECTED APPROACH FLAPS SETTING. SELECTION OF APPROACH FLAPS CAUSED NO MOVEMENT IN FLAP SYS. PILOT ATTEMPTED FLAP SELECTION ONCE MORE WITH NO LUCK. PILOT REFERRED TO CHECKLIST FOR FAILED FLAPS. PILOT ELECTED TO ABORT APPROACH & LANDING & DIVERTED BACK. PERFORMED NO FLAPS APPROACH & LANDING WITHOUT INCIDENT. DURING TROUBLESHOOTING, VERIFIED INOPERATIVE FLAP SYS & DISCOVERED APPROACH MICRO SWITCH PN V3-1 TO BE DEFECTIVE. OPTED TO REPLACE UP, APPROACH & DOWN MICRO SWITCHES, THREE EACH, DURING REPAIRS DUE TO CONVENIENCE. .