What was found
(CAN) ACFT WAS IN CRUISE WHEN CREW REPORTED THAT THE NR 3 ENGINE LOST POWER & SPOOLED DOWN BY ITSELF, SEVERAL ASSOCIATED MWS CAUTION LIGHTS ILLUMINATED. ACFT LANDED SAFELY AT ITS INTENDED DESTINATION. ACFT FERRIED HOME ON THREE ENGINES. MX FOUND THE NR 3 ENGINE SECONDARY OVERSPEED CONTROLLER AT FAULT. ACFT RUN WITH NO FURTHER OCCURRENCE OF DIFFICULTY. ACFT SCHEDULED IN FOR ITS HEAVY CHECK & HONEYWELL THEN REQUESTED THAT WE RING OUT THE ENTIRE OVERSPEED ELECTRICAL SYSTEM ON THAT & ALL OTHER ENGINES CONFIRMING THE FUNCTION & SERVICEABILITY OF THE OVERSPEED SYS. NO FAULTS HAVE BEEN FOUND TO DATE. OVERSPEED CONTROLLER THAT INITIALLY CAUSED PROBLEM HAS BEEN SENT TO HONEYWELL FOR ANALYSIS.