Our Sharp microwave/convection oven was connected to a special wall-mounted bracket by two very long bolts (about 15" long) that came up from the bottom of the oven. There's also a "lip" at the top of that bracket that matches one on the back of the oven. Once you remove those two long bolts, you then have to lift the oven about 1/4" to disengage those "lips" and free it. Have lots of support - that's a heavy beast. There was absolutely no shelf or other support at the top.
To replace it with a non RV model, we had to build a strong shelf to hang the new one from. Real pain.
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