As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AT GATE) 199793/1 - EXCESSIVE SMOKE FROM APU INLET AFTER APU SHUTDOWN FOR 3(?) MINUTES FIRE WARNING FOR SPLIT SEC AND THEN SILENCED ITSELF. INSPECTED APU INLET AND EXHAUST, PULLED APU COVER AND INSPECTED AREA NO DEFECTS NOTED. INSPECTED FIRE LOOPS, NO DEFECTS NOTED. (REMOVED AND REPLACED APU ASSY). (K)