What was found
EICAS AND MASTER WARNING EICAS RESOLVED ITSELF BEFORE QRH AND AGENT DISCHARGE COULD BE COMPLETED. UPON ARRIVAL AT SGF, IT WAS NOTED THAT THE FWD AND AFT CARGO COMPARTMENTS WERE LOADED WITH BULK FREIGHT, ALL THE WAY TO THE CEILINGS IN BOTH COMPARTMENTS. THERE WERE NO ALERTS NOR WARNINGS AT BLOCK IN, AND CARGO COMPARTMENT SMOKE DETECTION SYSTEMS TESTED NORMALLY IAW B757 AMM 26-16-00-5-0. FIRE/OVHT LOGIC/TEST PC CARD 6, M10427 IS COMMON TO BOTH THE FWD AND AFT SMOKE DETECTION SYSTEMS. REMOVED AND REPLACED FIRE/OVERHEAT PC CARD ASSY 6, M10427 IAW AMM 26-10-01-4-0. CARGO COMPARTMENT SMOKE DETECTION SYSTEM OPS CKS NORMAL PER AMM 26-16-00-5-0. AC OK FOR SERVICE.