What was found
FLT 2025 - OAK-DEN - AFTER BLOCKING OUT FROM PARKING, THE APU FIRE WARNING SOUNDED. THE CREW PERFORMED EMERGENCY APU FIRE CHECKLIST AND ACTUATED THE APU FIRE HRD BOTTLE. THE AIRCRAFT RETURNED PARKING WITHOUT ANY FURTHER DIFFICULTIES. MAINTENANCE INSPECTED THE APU AND FOUND NO EVIDENCE OF FIRE. MAINTENANCE DEFERRED THE APU AND APU FIRE WARNING SYSTEM AND THE AIRCRAFT WAS RETURNED TO SERVICE. ON 2/7/2001 THE APU FIRE HRD BOTTLE WAS REPLACED IN MHR. TROUBLESHOT THE FIRE WARNING SYSTEM. NO DEFECTS WERE NOTED. THE AIRCRAFT WAS RETURNED TO SERVICE. (M)