As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAX INFLIGHT - AFTER TAKEOFF CAPTAIN WAS UNABLE TO RAISE NOSE LANDING GEAR. RETURNED TO LAX AND LANDED WITHOUT INCIDENT. REMOVED PISTON AND INSPECTED. REPLACED STRUT. INSTALLED NEW SCHRADER VALVE AND O-RING. SYSTEM GROUND CHECKED NORMAL OPERATION.