What was found
AT FL320 CARGO FIRE LOWER AFT DISPAYED WITH MASTER WARNING, LEVEL 3 ALERT AND AURAL TONE. DISCHARGED BOTH BOTTLES DURING REMAINDER OF FLIGHT. ON ARRIVAL CHECKED AFT AND CTR CARGO COMPARTMENTS, NO SIGN OF FIRE OR SMOKE. MANUAL CARGO FIRE TEST CARRIED OUT, NO FAULTS OBSERVED. BOTH FIRE BOTTLES WERE DISCHARGGED AND AGENT LOW LIGHTS ILLUMINATED. AS A PRECAUTION NEED TO INOP SMOKE DETECTORS IN AFT AND BULK COMPARTMENTS, HENCE ALL 5 SMOKED DETECTOR UNITS DISCONNECTED. COMPLIED WITH EA 1-2612-146196, PART 2, REPLACED ALL 5 SMOKE DETECTORS IN CTR/AFT CARGO COMPAREMENT IAW MM26-14-01-4 AND OPS TESTED IAW MM26-14-01-5, FOUND OPS OK, NO FAULTS NOTED. SEE WRI 26-12/6207/6208 FOR CARGO FIRE EXTINGUISHER REPLACEMENT.