As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAINTENANCE REPORTED THE PASSENGER O2 MASKS AT 11 DEF AND 12 ABC FAILED TO DEPLOY DURING MANUAL MASK RELEASE OPS TEST. MAINTENANCE REPLACED PASSENGER OXYGEN MODULES AT 11DEF AND 12ABC PER MM 35-21-41-400-001. ACCOMPLISHED OPS TEST OF MANUAL MASK RELEASE PER 35-23-00-710-001. OPS NORMAL.