As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK/DECLARED EMERGENCY -- AFTER TAKEOFF LANDING GEAR WOULD NOT RETRACT, PERFORMED QRH PROCEDURE FOR LANDING GEAR LEVER LOCK SOLENOID FAILURE AND GEAR RETRACTED NORMALLY. REMOVED AND REPLACED LANDING GEAR HANDLE LOCK CYLINDER PER MM.