As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD INFLIGHT - AFTER TAKEOFF CREW RETRACTED NOSE GEAR AND EXPERIENCE A SEVERE NOSE GEAR DOOR VIBRATION. LOWERED GEAR AND VIBRATION REDUCED. RETURNED TO ORD AND LANDED WITHOUT INCIDENT. FOUND LEFT NOSE GEAR DOORS DOWN. PERFORMED NOSE GEAR DOOR INSPECTION WITH NO DEFECTS NOTED. SYSTEM GROUND CHECKED NORMAL OPERATION.