What was found
AT APPROXIMATELY V1 SPEED, THE NR 1 ENGINE FIRE WARNING LIGHT AND BELL ACTIVATED AND AT 800 FT AGL THE NR 1 REVERSER UNLOCK LIGHT ILLUMINATED. THE NR 1 ENGINE WAS SHUT DOWN PER IAW COM PROCEDURES AND FUEL WAS DUMPED. AIRCRAFT RETURNED TO MSP AND LANDED WITHOUT INCIDENT. MAINTENANCE RECONNECTED THE 15TH STAGE PNEUMATIC S-DUCT AND CHANGED NUMEROUS PARTS FOR OVERHEAT DAMAGE. SUBSEQUENT ENGINE RUN AT FULL POWER WAS NORMAL.