What was found
(SUPPLEMENTAL MRR) PILOT REPORTED WHEN LOWERED LANDING GEAR, NO LEFT MAIN GEAR CAME DOWN, CYCLED GEAR 3-4 TIMES, NO LEFT MAIN LANDING GEAR. ATTEMPT TO LOWER LT MAIN GEAR MANUALLY AND DID NOT WORK PROPERLY. TURNED HANDLE C/W 2-3 TURNS AND GOT DOOR LIGHT, WAIT 5 SECONDS AND TRIED TO CONTINUE TURN TO STOP, BUT HANDLE WOULD NOT MOVE. IT FELT BOUND. FINALLY, FORCED HANDLE UNTIL HEARD A CABLE BREAK. LEFT GEAR CAME DOWN AT THAT TIME. CHECK LEFT MANUAL EXTENSION FOR BROKEN CABLE OR SOMETHING. REPLACED LT MAIN GEAR LOCK ACTUATOR PER MM 32-30-00. REPLACED MLG CABLES PER 32-34-41. REPLACED MANUAL EXTENSION DRUM PER 32-34-71.