As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE 3 LOOP-A LIGHT ILLUMINATED IN-FLIGHT WITHOUT FIRE WARNING. FOLLOWED COM PROCEDURE AND LOOP-B TESTED SATISFACTORY. LOOP-A LIGHT WENT OUT WHILE PERFORMING COM PROCEDURE. CONTINUED FLIGHT USING LOOP-B DETECTION SYSTEM. REMOVED, INSPECTED, AND CLEANED CANNON PLUGS. OPS CHECKED GOOD.