As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOTS REPORTED, EXPERIENCED ENGINE VIBRATION WITH DECREASING N1 AND YAW AT FL380. PERFORMED ENGINE SHUTDOWN PROCEDURE PER QRH. MAINTENANCE REMOVED AND REPLACED NR 1 ENGINE S/N 889494 IAW MM REF 71-00-02. LEAK AND OPERATIONAL CHECKS GOOD. RII ACCOMPLISHED PER INSPECTOR.