As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FAULT LIGHT #1 ENGINE B LOOP. GROUNDED - YES. VERIFIED DISCREP FIRE DETECTION CONTROL UNIT SHOWS #1 ENG B LOOP UPPER FAN DETECTOR FAULT. UPON INSPECTION OF UPPER FAN DETECTOR ASSY. FOUND BROKEN B LOOP ELEMENT REF B737-800 AMM 26-11-01, REMOVED/REPLACED UPPER FAN FIRE DET ELEMENT ASSY. OPS NML REF AMM 26-11-00. GROUND VERIFICATION TEST GOOD.