As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE ENGINE FIRE PROTECTION TEST, FOUND NR 3 ENGINE SYS "B" LIGHT WON'T COME ON SYS "A" LT OK. FIRE DETECTION SYS ON NR 3 ENGINE SYS "B" DEFERRED IAW MEL 26-6 SYS "A" WORKS OK PLACARD INSTALLED CTRL NR 18526. WORKING DMI (18526) NR 3 ENGINE FIRE DET SYS "B" LT INOP. NR 3 ENG SYS "B" LOOP CHECK FOUND LOOSE TERMINAL, TIGHTENED SAME IAW MM 26-11-0, CHECKS GOOD PLACARD REMOVED.