As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TRANSIT CHECK, THE FIRST OFFICER OXYGEN TEST WAS NOT SATISFACTORY WITH YELLOW LIGHT TURNED OFF. MAINTENANCE PERFORMED REVISION DETECTING THE FIRST OFFICER OXYGEN MASK DAMAGED. THE OXYGEN MASK WAS SWAPPED WITH THE OBSERVER`S IAW AMM 25-11-00 AND THE OBSERVER SEAT OXYGEN STOWAGE WAS DEFERRED. THE OBSERVER`S OXYGEN MASK WAS REPLACED IAW AMM 35-12-85, TESTED CORRECT AND THE REPORT WAS CLOSED.