As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ACCOMPLISHING ENGINE/APU FIRE DETECTION CONTROL MODULE BITE TEST. NR 2 ENGINE FAULTED UPPER FAN B LOOP. ACFT GROUNDED. REMOVED AND REPLACED NR 2 ENGINE UPPER FAN FIRE DETECTOR ASSEMBLY IAW AMM 26-11-01. GROUND VERIFICATION TEST PASSED IAW AMM 26-11-00-710-801. NR 2 ENG DETECTOR SWITCH RETURNED TO NORMAL CONFIGURATION.