As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOWER AFT CARGO FIRE WARNING LIGHT RANDOMLY COMES ON & OFF. NO OTHER LOWER AFT CARGO FIRE WARNINGS OR INDICATIONS. TROUBLE SHOT & FOUND LOWER AFT CARGO FIRE WARNING SWITCH DUST. CLEANED & RECONNECTED THEN AFT CARGO FIRE SYS CHECKED OK IAW AMM 26-23-00.