As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING MTC PRE-FLIGHT, CREW O2 SYSTEM PRESSURE EICAS INDICATION INACCURATE. PREVIOUSLY REPLACED VOLTAGE AVERAGING UNIT DETERMINED TO BE BAD FROM STOCK. DEFERRED CREW O2 PRESSURE INDICATION EICAS PER MEL 35-11-2-1. PLACARDS INSTALLED MBCB07-18-2026. MUST BE REINSPECTED PRIOR TO EACH FLIGHT. MX PROCEDURE ACCOMPLISHED PER MPM 35-11-2-1. 1750 PSI BOTTLE NR 1 1850 PSI BOTTLE NR 2. ACFT RETURNED TO SERVICE.