As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 4 ENGINE FIRE WARNING MESSAGE. COMPLIED WITH QRH, AIR TURN BACK, IN-FLIGHT SHUTDOWN. MX CURRENTLY TROUBLESHOOTING CARDS. UPPER FWD LOOP & AMP AFT LWR REPLACED. MX TO REPLACE LWR FWD & AMP UPPER AFT. INSPECTED PER EO 4426A052. ACCOMPLISHED ENGINE BLEED CHECKS PER MM. ALL SYSTEMS OPERATE NORMAL.