As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED THAT A FIRE SQUIB WAS FAILING TO TEST. MAINTENANCE INSPECTED AND REPLACED THE FIRE WARNING CONTROL UNIT IN ACCORDANCE WITH DORNIER MAINTENANCE MANUAL 28-00-00. OPERATIONAL CHECKS WERE PERFORMED AND THE AIRCRAFT WAS RELEASED FOR SERVICE.