What was found
AT TOUCHDOWN, APU FIRE LIGHT, AGENT AUTO FIRED. APU FIRE HANDLE PULLED. APU MASTER SW WAS OFF AND APU WAS NOT ON/RUNNING. UPON FURTHER INVESTIGATION, DISCOVERED EVIDENCE OF A FIRE IN THE APU COMPARTMENT. PLUG P18 FROM THE MONOPOLE ASSY IS MELTED AND BURNED. THE MONOPOLE ASSY C/P IS BLOWN APART AND BURNED. NUMEROUS WIRE BUNDLES ON APU HARNESS ARE BURNED AND SCORCHED. REMOVED AND REPLACED APU FIRE EXTINGUISHER BOTTLE. INSPECTED AREA FWD OF APU COMPT, THRU ACCESS DOOR 313AL, NO VISIBLE SIGNS OF HEAT OR FIRE DAMAGE, NO VISIBLE BLISTERING. REMOVED & REPLACED APU. SEE ALSO EA 6-4912-113204 FOR ADDITIONAL WORK C/W.