What was found
LOWER AFT CARGO SMOKE WARNING ILLUMINATED IN FLIGHT. RAN QRH. DISCHARGED BOTTLE-1, LANDED IN LCK IN 20 MIN. SECOND BOTTLE DID NOT AUTO-FIRE AS PER 25 MIN REQUIREMENT. CFR CREWS DETERMINED NO FIRE PRESENT. FOUND ALL TEST LIGHTS ON AFT LOWER CARGO COMPARTMENT CEU, COULD NOT GET THEM TO GO OUT UNLESS C/B'S WERE PULLED, SUSPECT BAD AFT LOWER CARGO CEU. REMOVED AND REPLACED AFT LOWER CARGO CEU REF BOEING AMM CP 26-16-012-2. TESTS GOOD. REMOVED AND REPLACED NR 1 FIRE BOTTLE AND AFT PIT SQUIB REF BOEING AMM CP 26-16-014-2. OK FOR SERVICE.