What was found
DFW - FLT 963 - EN ROUTE DFW-GRU - AT GATE DURING ENGINE START APU COMPRESSOR STALLED SEVERAL TIMES ACCOMPANIED BY APU FIRE WARNING INDICATION. ACCOMPLISHED EMERGENCY PROCEDUES PER CHECKLIST. APU LIGHT EXTINGUISHED AFTER PROCEDURES ACCOMPLISHED. REPLACED APU FIRE BOTTLE AND SQUIB. ACCOMPLISHED TROUBLESHOOTING PROCEDURES. NO EVIDENCE OF FIRE FOUND. RAN APU. NO FAULTS NOTED. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)