Hi,Welcome to Just Answer, My name is XXXXX XXXXX forward to helping you today.
These microwaves have an in-line fuse inside the microwave itself, this is located behind the control panel, this is what the fuse look like, you need to open up the control panel to get to the fuse, along the top there is a grill plastic vent grill, there are two small Phillips head screws holding to grill in place remove them and there will be a screw holding the control panel (touch pad), at the top, remove that and slide the control panel up to on hook it so it will hinge down, the fuse located behind the control panel. Be extremely careful while working on a microwave inside the control panel area, make sure the microwave is unplugged up in the cabinet above the microwave. Lowe's sells the fuses just bring your old fuse with you and find you the replacement fuse. Thanks, Bryan