As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLE FLT 5835 THE CREW REPORTED A ENGINE NR 1 FIRE DETECT FAIL MESSAGE IN FLIGHT. MAINTENANCE INSPECTED AND COULD NOT DUPLICATE PROBLEM. REPLACED THE NR 1 ENGINE EXTERNAL HARNESS AND THE NR 1 ENGINE FIRE LOOP AND THE NR 1 PYLON FIRE LOOP. OPERATIONAL CHECKS WERE GOOD.