What was found
AT TOUCHDOWN, APU FIRE, AGENT AUTO FIRED. APU FIRE HANDLE PULLED. APU MASTER SWITCH OFF, APU NOT ON. UPON FURTHER INVESTIGATION, DISCOVERED EVIDENCE OF FIRE IN APU BAY. CONNECTOR P18 AT MONOPOLE ASSY IS MELTED/BURNED. NUMEROUS WIRE BUNDLES ON APU HARNESS ARE BURNED & SCORCHED. APU FIRE BOTTLE AUTO DISCHARGED UPON TOUCHDOWN. APU ENGR APPROVED. APU R & R GTCP331-250H, PERFORM STRUCTURAL INSPECT OF APU BAY AFTER APU REMOVED AND CLEANING PER MM 53-19-11-6 & SRM 53-19-12. PURGED APU DRAIN LINE WITH DRY N2. NO EVIDENCE OF BLOCKAGE. R & R OF APU BLEED VALVE, APU AIR INTAKE FLAP ASSY, FWD MOUNT ROD PER AMM.