As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB LWR AFT CARGO FIRE WARNING LIGHTS AND BELL CAME ON INTERMITTENTLY. PERFORMED QRH PROCEDURE, EMERGENCY RETURN. INSPECTED AFT LOWER CARGO COMP. AND CARGO. FOUND NO EVIDENCE OF FIRE OR SMOKE. FOUND SMOKE DET NR 3 INTERMITTENT ON TEST. REPLACED BULB AND OPS CHECKED CARGO SMOKE DET SYS. IAW MM 26-16-00. OPS CKS NORMAL.