As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND MASTER FIRE WARNING MODULE IN THE FLIGHT DECK FAULTY TEST SWITCH STUCK IN TEST MODE. REPLACED ENG APU CTL PANEL PER 26-00-01-000-801. INSTALLED PANEL PER 26-00-01-400-801 COMPLIED UP TO SUBTASK 26-00-01-710-001 ROTABLE PARTS CHANGE WAS INDICATED - TT 1314434 SN OFF 8897 MODULE, FIRE DET OFF 29-3111-9-0013 8897 ON 29-3111-9-0013 3337.