As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLIMBING THROUGH FL 230, THE AFT CARGO FIRE ALARM WENT OFF, COMPLETED THE CARGO FIRE PROCEDURE IAW QRH, PEFORMED AIR TURNBACK TO DEPARTURE. PERFORMED CARGO FIRE SUPESSION SYSYTEM OPERATIONAL TEST IAW AMM SUPPLEMENTAL DOC. N-0009-01 AND AMM 29-19-00. SYSTEM TESTS OK.