As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON T/O FROM ATL NOSE LANDING GEAR DID NOT RETRACT. GEAR WAS LOWERED PER QRH, LOUD NOISE WHEN GEAR LOCKED DOWN. EMERGENCY DECLARED, A/C RETURNED TO ATL LANDED SAFELY. FOUND AFT NLG DOOR RT HINGE PIN SHEARED. REMOVED AND REPLACED HINGE PIN.