As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ROUTINE MAINTENANCE, THE OXYGEN AUTO-DEPLOY SYSTEM WAS ACTIVATED. ALL MASKS FAILED TO DEPLOY. THE CAUSE WAS THE NEW HEADLINER MATERIAL THICKNESS WHICH PREVENTED THE ACTUATOR PLUNGER FROM CONTACTING THE STRIKER PLATE ON THE MASK CONTAINER. THIS IS THE FIRST TIME THIS SYSTEM HAD BEEN ACTIVATED SINCE THE AIRCRAFT HAS BEEN RE-TRIMMED ON 11-11-93.