As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON DESCENT NR 4 ENGINE FUEL CONDITION ACTUATOR CIRCUT BREAKER STARTED SMOKING, CIRCUT BREAKER PULLED, SMOKE STOPPED. REMOVED AND REPLACED THE NR 4 FUEL CONDITION ACTUATOR CIRCUIT BREAKER IAW B747-200 MM 24-50-01 AND OPS CHECKED GOOD IAW B747-200 MM 76-11-00 WITH NO DEFECTS NOTED.