What was found
EWR - AFTER TAKEOFF FROM NEWARK FLIGHT 3340, REPORTED ELECTRICAL SMOKE FILLING CABIN FROM RIGHT FRONT OVERHEAD. CREW AIR RETURNED TO EWR AND EMERGENCY DECLARED. AIRCRAFT LANDED UNEVENTFULLY. MAINTENANCE TROUBLESHOT AIRCRAFT, FOUND READING LIGHT TRANSFORMER OVERHEATED AND BECAME INOPERATIVE. AIRCRAFT RELEASED UNDER MEL, P/N 8ES004514 PLACED ON ORDER. (M)