As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF FROM NBO, NR 2 TRANSFORMER RECTIFIER WENT INOP. DUMPED 8200 LBS OF FUEL AND ACCOMPLISHED AIR TURN BACK TO NBO, AIRCRAFT LANDED WITHOUT INCIDENT. INSPECTED ELECTRICAL SYSTEM FOUND NR 2 TRANSFORMER RECTIFIER HAD BROKEN WIRE, REPLACED NR 2 TRANSFORMER RECTIFIER SYSTEM OPS CHECKED GOOD PER MM CH 24-30.