This is the second time I fixed the exact same issue. For 68 bucks and a quick in and out, it was worth it. The microwave is fine otherwise, a very nice unit. Saves me from selecting a new one that I like, taking the old one down, new mounting hardware for a new one etc.
You have to take the guts out of the old one, 2 circuit boards and a metal shield, unplug a LOT of cables, move them to the new unit and reinstall to this panel, then back on the microwave. IT IS NOT a pop out, pop in thing.
HOWEVER, so what, the stuff comes in and out with very few screws, cable connectors are pretty much unique to each cable, so you can't mix em up. A little patience, maybe number the cables when you remove them, really no big deal if you have it in you.
The diy repair is worth the effort, the panel will only last two years with normal use.