
"Although I bought a new Kitchenaide built in microwave just a few years ago and noticed the electronic numbers are now sketchy and it quit heating so gonna have to remove it and see what little piece is the culprit."

Hopefully, your Kitchenaide microwave (built in) is a (stand alone) unit and not part of a combo/microwave/oven built in unit.

If so, your problems are expanded as I recently found out with a heating problem with ours. Fortunately, we were able to find a reasonable dealer that did not try to gouge us on the repair. The whole unit has to be slid out of the wall to work on it (very heavy, took the rep and me both to lower it on to my Coleman cooler) instead of all the way to the floor. The damn thing is made with no consideration for any (follow on) repair work as certain parts and areas are extremely hard to get to.
Ours broke due to the fan that cools the magatron failing........thus wiping out the magnetron too.
Advice..........Go with a double oven as a built in and/or make sure your microwave selection is merely a stand alone unit in case of repair needs.