As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB OUT, FLIGHT CREW NOTED SMOKE COMING FROM THE NR 3 VOLTAGE REGULATOR. ISOLATED IAW QRH, RETURNED TO DEPARTURE AND LANDED. REPAIR ACCOMPLISHED BY REPLACING NR 3 GENERATOR, VOLTAGE REGULATOR, AND GENERATOR CONTROL PANEL IAW LOCKHEED SMP581 24-20.