As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DETECT FIRE & OVERHEAT NR 3 EICAS MSG AFTER TAKEOFF. TROUBLESHOOTING CUT OUT WITH FIRE DETECTOR EXTENDER CARD IN LOOP A & B POSITIONS. LOOP A FOUND INTERMITTENT CONNECTION ON LOWER AFT RT SIDE DETECTOR TS682. DETECTOR ASSEMBLY REPLACED IAW AMM 26-11-02. LOOP A NOW SERVICE LOOP B INOPERATIVE IAW 697713 & M8, PN OFF 901907 & SN OFF 315F, PN ON 901907 & SN ON 665.