As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW O2 PRESSURE AT 1750 AS REPORTED BY CREW. O2 SERVICED EARLIER TODAY. PERFORM VISUAL AND AUDIBLE CHECK OF O2 CONNECTORS AT BOTTLE. CHECKED SECURITY OF ALL 4 CREW O2 MASKS. FOUND LEAK IN THE 1ST OBSERVERS OXYGEN-MASK STOWAGE-BOX. WILL NEED STOWAGE BOX (UAL PCN 649-0376). CAPPED OFF LINE TO STOWAGE BOX AND NO FURTHER LEAKS NOTED. OK TO CF STOWAGE BOX INOP TO ORD FOR REPLACEMENT. REPLACED STOWAGE BOX, LEAK CK'D GOOD.