As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK. FLIGHT CREW REPORTED NR 2 FIRE WARNING BELL SOUNDED AND LIGHT ILLUMINATED. LIGHT EXTINGUISHED WITH THRUST REDUCED TO IDLE. ALL ENGINE INDICATIONS APPEARED NORMAL. REPLACED NR 2 ENGINE UPPER FIRE SENSING ELEMENT. REMOVED PLACARD.