After looking up on the computer a schematic of the unit, all that was needed was removing four screws to remove the top and side cover which was one piece. Next was removal of electrical connection to burned out lamp, then removing burned out lamp and installing the new lamp and reconnecting electrical connection. Job was complete after reinstalling the cover.
Microwave now working with new lamp lighting when in use.
Continuity checks showed the flame sensor was open. Schematic notes it opens at 217 degrees and closes at 30 degrees. Removed sensor and placed in freezer for twenty minutes. Tested sensor and it was now closed, reinstalled and microwave worked normally. Ordered new sensor in case the original is operating at too low a temperature.
First, I read the PartsSelect DIY report by Linda, Warsaw, IN. With confidence, I purchased the magnetron. Upon receipt, I took the built-in microwave out of the cabinet, set the unit on the kitchen floor, and was stopped cold by the Safety Torx nuts on the reverse of the unit. Borrowing the right wrench allowed the 20 minute start-to-finish part changeout and reinstallation of the unit in the cabinet to proceed. The old magnetron was the defective part. Discovery of the 10-year Parts-Only warranty on the less than 10-year old unit was insufficinet to guide me to take the unit in for their Labor bill to repair. New part in hand, it just was that easy - and assumed to be no less expensive.
