As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING OVHT/FIRE TEST, ENGINE #2 DOES NOT TEST PROPERLY WITH DETECTOR SWITCH IN BOTH. GROUNDED - YES. REPLACED ENG 2 M1757 AND M1758 ENG FAN FIRE DETECTORS ASSY. REF AMM 26-11-01-400-802, OPS NML REF AMM 26-10-00-710-801. ACCOMPLISHED VISUAL INSP ON THE # 2 ENG CORE SECTION , NO FAULTS FOUND. SYSTEM GROUND VERIFICATION CHECK'S SUCCESSFUL.