As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TEST FLT, NR 2 ENGINE FIRE LOOP A FAULT IN FLT. REMOVED AND REPLACED ENGINE AND APU FIRE PANEL FOR TROUBLESHOOTING. NO CHANGE, INSTALLED ORIGINAL PANEL IAW AMM. NR 2 MAIN BATTERY WAS FOUND INOPERATIVE AND IS THE SOURCE OF THE POWER FOR THE NR 2 ENGINE LOOP A. BATTERY WAS REPLACED. PERFORMED ENGINE RUNS TO TEST FIRE LOOP SYSTEM. NO FAULTS FOUND AFTER 10 MINUTE RUN AT BOTH IDLE AND HIGH POWER.