What was found
YIP - FLT 12323 - LANDING GEAR WOULD NOT EXTEND (INDICATION 3 RED LIGHTS AND NO GREEN LIGHTS). GEAR HANDLE CYCLED TWICE WITH NO RESULT. CREW EMPLOYED AFM "PROCEDURE A" TO EXTEND LANDING GEAR AND LANDED WITH 3 GREEN LIGHTS. NOTE: AIRCRAFT WAS ARRIVING AT YIP WHEN THIS DIFFICULTY WAS ENCOUNTERED. PROBLEM NOT DUPLICATED DURING GROUND RETRACTION TESTS. PERFORMED 'VOLTAGE DROP TEST' OF LANDING GEAR DOOR SWITCHES IAW MM PROCEDURES 32-60-10. NLG DOOR ACTUATOR SWITCH FOUND BAD. REPLACED WITH SERVICEABLE PART. LANDING GEAR CYCLED IAW MM 32-30-00 WITH NO DEFECTS NOTED. (X)