What was found
LAX FLT 1 EN-ROUTE PIT TO LAX, DURING APROACH, THE LANDING GEAR DID NOT INDICATE DOWN AND LOCKED. THE FLT PERFORMED A GO-AROUND, AND THEN MANUALLY EXTENDED THE LANDING GEAR. THE AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE PERFORMED TROUBLESHOOTING PROCEDURES AND CYCLED THE LANDING GEAR NUMEROUS TIMES. THE PROBLEM COULD NOT BE DUPLICATED. THE MANUAL EXTENSION HANDLE WAS RESET. AIRCRAFT OK FOR SERVICE.