What was found
DURING PREFLIGHT INSP, CREW REPORTED THAT APPROX 5 MINUTES AFTER CONNECTING GROUND POWER, SMOKE WAS WITNESSED COMING FROM THE TOP OF THE GALLEY. MX PLACED GALLEY LIGHTING ON NEF -GL-01, AND THE ACFT WAS APPROVED FOR RETURN TO SERVICE. LATER THAT DAY AIRCRAFT RETURNED TO DEPARTURE WHERE MX REMOVED AND REPLACED THE LIGHTING BALLASTS ABOVE THE GALLEY CEILING, OPS TESTED WITH NO DEFECTS, AND THE ACFT WAS APPROVED FOR RETURN TO SERVICE.