As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT APU HAS A HISTORY OF THE FIRE FAULT AND CHECK FIRE DETECT LIGHTS ILLUMINATING AFTER SHUTTING DOWN THE APU. MAINTENANCE HAS COMPLIED WITH SEVERAL CHECKS AND HAS REPLACED THE RELAYS 2623-K1 AND 2622-K2.SYSTEM HAS NO HISTORY SINCE. SYSTEM OPERATIONAL CHECK GOOD.