As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, AND IN CLIMB THE PILOT ATTEMPTED TO RETRACT THE LANDING GEAR BY PLACING THE HANDLE IN THE RETRACT POSITION AND THE GEAR REMAINED IN THE DOWN AND LOCKED POSITION. RETURNED THE HANDLE TO THE DOWN POSITION AND DIVERTED AND LANDED WITH NO INTERUPTIONS.