As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURN AIR TURN-AROUND FOR HEAVY VIBRATION UNDER COCKPIT AFTER GEAR RETRACTION. GEAR LEVER SELECTED TO DOWN VIBRATION STOPPED. FOUND LT NOSE GEAR DOOR OPEN ON TAXI IN 952847. SUSPECT LT FWD NOSE GEAR DOOR LINK FAILED. REPLACED LT FWD DOOR LINK. JACKED ACFT. CYCLED GEAR SEVERAL TIMES. OPS AND INDICATION OF NOSE GEAR AND DOORS CK SATISFACTORY.