As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING INSPECTION PER TASK CARD NG-36EO-22817-1 AND NG-36EO-22817-2, FOUND THE NR 1 ENGINE 5TH STAGE VALVE FLAPPER STICKING. INSPECTION PASSED ON THE NR 2 ENGINE VALVE, GROUNDED - YES. REMOVED AND REPLACED THE NR 1 ENGINE 5TH STAGE CHECK VALVE IAW AMM 36-11-02.