As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER DEPARTURE, LANDING GEAR WOULD NOT RETRACT. LANDING GEAR HANDLE WOULD NOT MOVE. INSPECTED LANDING GEAR ASSY AND FOUND ON THE RT MAIN GEAR THAT THE COLLAR WAS MISSING FROM THE SQUAT SWITCH. R & R THE RT MAIN SQUAT SWITCH. OPS CHECK WAS GOOD. WORK PERFORMED IN REF TO THE MM 32-60-00.