As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN CARGO FIRE EICAS ON CLIMB OUT. PERFORMED QRH PROCEDURE AND RETURNED TO CVG. MSG WENT AWAY ON SHORT FINAL. PERFORMED MAIN DECK CARGO FIRE TEST. SUSPECT M10427 FIRE OVHT LOGIC TEST CARD. REMOVED AND REPLACED M10427 FIRE OVHT LOGIC TEST CARD IAW 26-10-01. OPS CKS GOOD.