As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE YEARLY INSPECTION OF THE LIFE VEST, THE WATER ACTIVATED BATTERY FOR THE LOCATING LIGHT HAD EXPANDED & BURST OPEN. THIS MADE THE LIGHT INOPERABLE. ACCORDING TO THE EAM SERVICE INFORMATION SIL-25-104 ,THIS VEST COULD HAVE A INSPECTION INTERVAL OF FIVE YEARS, WHICH MEANT THE LIGHT COULD HAVE BEEN INOPERATIVE FOR FOUR YEARS.