As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED APU FIRE INDICATION (EICAS RED AND CHIMES) SHORTLY AFTER APU WAS STARTED IN FLIGHT ON APPROACH TO MGM. APU WAS SHUT DOWN AND ALL ALERTS CLEARED. CREW LANDED IN MGM WITHOUT INCIDENT. MAINTENANCE INSPECTED APU AND ENCLOSURE. NO EVIDENCE OF FIRE WAS FOUND. MAINTENANCE PERFORMED CHECKS OF APU USING AIRCRAFT MAINTENANCE MANUAL. AIRCRAFT WAS RELEASED FOR SERVICE.