Samsung microwaves run under the ME, MC, and MS model prefixes. Broadly, ME covers many over-the-range and countertop models — a representative over-the-range unit is the ME21M706BAS — MC covers convection and combination units, and MS covers a range of countertop models.
The characters after the prefix encode cavity size (the “21” above tracks to a 2.1 cubic-foot class), the wattage tier, the generation, and a finish suffix. Over-the-range models add a built-in vent fan and a cooktop light beneath, while higher tiers add Sensor Cook humidity control that adjusts time automatically, a PowerGrill or true convection element for browning, a ceramic enamel interior for easier cleaning, and Bespoke finishes on select models. The rating plate carrying the full model and serial number is inside the door frame or along the interior cavity wall, and over-the-range units also carry one behind the lower grille, so it is readable without uninstalling the unit. The serial number on that plate dates the build, useful because Samsung refreshed magnetrons and door-interlock assemblies within single model runs.
Noting whether your microwave is over-the-range or countertop, and recording the complete model-and-serial string, is what confirms the correct magnetron, door interlock switch, sensor, or control board — parts that differ significantly between the vent-hood and countertop designs and that Samsung has revised across model years. On an over-the-range unit it also helps to note the mounting and duct direction — recirculating or vented — since the fan housing and charcoal-filter parts differ, and the serial confirms which generation of blower the unit shipped with. Have that number ready before you book microwave repair for a clear, upfront quote, and any high-voltage work is left to the technician.