As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 3 ENGINE FIRE LOOP INDICATION. FLT DIVERTED. TRIED NEW FIRE DET CARD YL PA12, NO HELP. RETURNED TO ORIG. TROUBLESHOT LOOP ASSY PER WDM26-11-34, FOUND UPPER AFT LOOP TS681 (A) TO (GRND) NOT OPEN. REPLACED UPPER AFT FIRE DETECTOR ASSY (TS681), GROUND TEST NORMAL, SYS OK.