As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OXYGEN HIGH PRESSURE INDICATION AMBER ON DOOR, READING 310PSI AND DECREASING SLOWLY. SERVICED TO FULL EARLIER IN DAY. FOUND FIRST OBSERVERS SEAT OXYGEN BOX NOT TESTING AND ALLOWING AIR TO MASK FULL TIME. REPLACED BOX AND OPS OK. O2 PRESSURE HOLDING. ALSO REPLACED O2 MASK.