As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A LOUD POP ACCOMPANIED BY EXCESSIVE NOSE WHEEL VIBRATION OCCURRED DURING GEAR RETRACTION AFTER TAKEOFF. FLIGHT RETURNED TO MEM AND LANDED WITHOUT INCIDENT. FOUND THE RIGHT NOSE GEAR DOOR IN DOWN POSITION AND DOOR STOP CABLE BROKEN. REPLACED THE RIGHT NOSE STRUT AND DOOR STOP CABLE. AIRCRAFT RETURNED TO SERVICE.