What was found
ON TAXI INTO CAN TX RAMP, HAD CARGO FIRE LWR FWD LEVEL 3 ALERT. COMPLIED QRH CALLED FIRE DEPT, ASKED FOR FX MECHANIC TO INSPECT EXTERIOR AIRCRAFT, NO FIRE ACTUALLY OBSERVED. REMOVED AND REPLACED LOWER CARGO NR 1 FIRE BOTTLE AS PER AMM 26-22-01-4, AND ALSO REMOVED AND REPLACED TWO DISCHARGE CARTRIDGES AS PER AMM 26-22-04-801. PERFORMED THE OPS TEST OF THE LOWER CARGO SMOKE DETECTOR IAW AMM26-14-01-5, FOUND NORMAL. SO REPLACED THE 5 EA DETECTORS OF FWD LOWER CARGO (JUST REQUIRED IN THE TSI 26-12/4016) IAW AMM 26-14-01-4, AND PERFORMED THE OPS TEST IAW AMM26-14-01-5, FOUND NORMAL.