What was found
THE RIGHT IDG BECAME INOPERATIVE. THE APU WAS STARTED, HOWEVER IT WAS REPORTED THAT THE ELECTRICAL SYSTEM WAS UNSTABLE. THE FCU HEADING FROZE AND NEW HEADINGS WERE NOT ACCEPTED BY THE AUTOPILOTS NOR THE FLIGHT DIRECTOR. IN ADDITION, THE CREW REPORTED AN ELECTRICAL SMELL IN THE MID GALLEY. ALL GALLEY EQUIPMENT WAS SECURED AND THE SMELL ABATED. FLIGHT RETURNED TO PHL AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED GHE FCU FOR THE NAVIGATION PROBLEM. NO CAUSE WAS FOUND FOR THE MID GALLEY ODOR. THE MAIN CAUSE FOR THIS EVENT WAS THE ELECTRICAL PROBLEM. THE RIGHT GCU AND RIGHT WC-1 WIRING HARNESS WERE REPLACED. (M)