What was found
IN FLIGHT OUR FA ATTEMPTED TO USE THE MICROWAVE TO WARM PASSENGER FOOD. WITHIN 5 SECONDS OF USE, THE MICROWAVE BEGAN TO ARC INSIDE ON THE TOP, MADE A HIGH PITCH SQUEELING SOUND, AND GAVE OFF AN ACRID SMELL. WE STOPPED THE PROCESS AND ISOLATED THE CIRCUIT VIA THE GALLEY TOUCH SCREEN BREAKER. REMOVED THE MICROWAVE PN:400-1409-01-L, SN: 06-11-39952 DUE TO INTERNAL ARCING AND INSTALLED THE REPAIRED MICROWAVE PN: 400-1409-01-L AND SN: 07-03-40637. PERFORMED OPS CHECK OF MICROWAVE AND THE OVEN AND CHECKS WERE SATISFACTORY. CLOSED ACCESS AND RETURNED AC TO ITS ORIGINAL CONFIGURATION. WORK PERFORMED IAW SMM 25-30-66.