Noted on partselect.com that someone else with this problem, found it to be secondary door switch. There are three door switches in this model, but online info noted that one of the three might feel "soft" (in my case, one switch clicked in a rather "jiggly" way, the other two were strong decisive clicks.) To access the door switches on this model was the only difficult part. First use a torx bit to remove the two torx screws below the latches inside the microwave. This frees the latching part inside, that holds the door switches, which you will remove after you take off the control panel. The top grill has to come off before you can remove the door panel. Remove the screws above the grill, on the microwave top cover, The grill on this model is covered with a panel that moves out when it vents. After removing the two top screws, the covered grill vent slides left to remove. Be careful, as the sliding tabs are plastic. Wiggle and jiggle it, to slip it off. Below the removed grill, is a small metal grill with one screw in lower center. Remove that screw, and wiggle that out. You'll then see the one screw that holds on the control panel. Remove this screw, and lift the control panel up to remove. Again, go slowly and gently, as the bottom tabs holding the control panel in, are also plastic and easily broken. Lay the control panel on something, (I used the coffee maker) and pull out the wire bundles tucked on the left, that are attached to the latching panel. Wiggle the latching panel gently to lift it up off of it's plastic tabs and pull it out towards you, so you can see the three door switches. Each switch (part number WB24X829) has a little black switch on it. Feel each switch with either your finger, or a screwdriver to see which one doesn't "click" strongly. The weak one is the one you will replace. The door switches are fitted into a tab, and plugged into their wires. Remove the defective switch, pull out the wires, and replace it with the new switch, plugging back the wires, and slipping it back into it's plastic tabs. Then put everything back together in reverse order. The entire job took me fifteen minutes EXCEPT for figuring out how to slide off the upper grill, which I have told you. A repairman would have cost $150, the part was $18. AND, there's a good chance, the other two switches will get "used up" in the next year or so as well, so I'll be ready next time. Thank you, Partselect, why work all day, to make money, only to give it to somebody else, for fifteen minutes of work. All I needed was the knowledge.