As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ATTEMPTING TO DEACTIVATE THE LAV E LAVATORY SERVICE UNIT (LSU), THE OXYGEN GENERATOR PULL-CORD WAS INADVERTENTLY ENGAGE AT A TIME WHEN SAFETY PIN WAS NOT INSTALLED. DESPITE THIS UNINTENTIONAL ACTIVATION OF THE PULL-CORD, THE OXYGEN GENERATOR DID NOT INITIATE OR DISCHARGE OXYGEN. GROUNDED - YES. REMOVED AND REPLACED LAV E LSU OXYGEN CYLINDER REF AMM 35-22-51.