MT4155SPB3 Whirlpool Microwave - Instructions

ordered a new tray

Watched a you tube video prior to installing new switch. Followed the video which gave me confidence i was up to the task. After removing the touch pad I found my design was not exactly like the you tube model but I found the defective switch, replaced it and put the microwave back together. Works great. Again watch the videos

Remove from cabinetry, take cover off and had a very difficult time removing the plastic form that has the switched in. Replace the lowest of all the switches, and then again very difficult time getting the plastic form back in. Some of the plastic even broke during the process but not any that could prevent it from working as it did before. I had ordered a fuse, 2 packs of 2 switches as there are 3 switches but only had to use 1 to get it working again. Tested after switch install, put the cover back on and reinstalled in the cabinet.

Replaced Door latch Bracket.
Filed a bit off the bracket connection fingers so to fit into the slot.

discovered upon further inspection the the plastic shaft coming out of the turning motor was melted. Had to stop repair and order that part

Removed M/W oven case/cover. Identified part needed. Found part online with in 2 minutes, ordered new door latch actuator, installed with part arrived within two minutes, reattached case/cover, reinstalled M/W.

This plastic door latch bracket controls the door opening. Ours broke after 7 years of use. Probably just the plastic fracturing after years of use. Hardest part is finding the special driver to unscrew the housing around the microwave so that you can get to the control panel. Ask for something that looks like an allen wrench with a hole in the middle. I took a picture of the screw in the microwave and brought it to a big box store and asked for the correct driver. I have a feeling that a "real" hardware store (like Ace or TrueValue) may have been able to just direct me to the correct screw driver but I'm cheap so I though a big box store would be less expensive for a tool that I may never use again. Once you get the correct screw driver, opening the microwave is pretty easy. MAKE SURE THE MICROWAVE IS UNPLUGGED BEFORE YOU GO ANY FURTHER. There are a number of these "special" screws (4 to 6) and some regular screws to remove. Once you pull the housing off the microwave look at the release latch inside (behind the release press plate). You should be able to jiggle it out especially since it is probably broken on one side. Be sure to find and remove all the broken pieces. Mine had just the main latch and a small piece that broke off. Pull it out and you are ready to put the new one in. It is a little difficult putting the new latch bracket in. Try inserting one side into the holder hole and very gently pressing the other side in. Be patient; with a little pressure it will snap in. Then you simply put the housing back on, put the screws in and every thing should work. $20 bucks for the part and a half hour of work (after you find that special screw driver) is much better than buying a new microwave. Good luck!

Since others reported similar problems and it was just the fuse we tried that first. That wasn't the problem so we ordered the Door Interlock Switch Kit. Shipping was very fast! Our microwave had 3 switches. My husband asked how to know which one to switch. I read that one person just did process of elimination. Luckily ours worked on the first change out! So happy to have stumbled across this site and not have to buy a whole new microwave.

The door was not engaging the micro switches properly no doubt from 10+ years of wear. The upper switch removed fairly easily but take care not to tweak the plastic brace too much or it will snap. The lower one was the tricky one. After much examination I noticed that the trick to remove it was underneath the brace. Take a butter knife (no joke) and insert it just under the old micro switch and gently press down twisting the micro switch every so slightly til it releases. The replacements snap back in with no trouble. The microwave is working much better now, though not perfect.

Had to remove 3 screws that held the case in place,it removed easily. The control panel that the door latch was locked into required removing two screws and then lifting up slightly while pulling forward. This allowed enough room to put the new door latch bracket into place. Then re-assemble in reverse order. Total time about 30 minutes.

Followed the instructions that others with a similar problem had written about. Their experience was very helpful. My experience with Part Select was the best! Part recived in less than 24 hours. Happy household, wife thinks I'm worth keeping!

I started by calling a reputable service company to diagnose my problem. The repair tech told me it was the magnetron and it was a "very difficult" repair that required two people because the over-the-range unit needed to be taken down. I asked for a detailed estimate. He quoted $550 including parts and labor. After he left, I researched the part costs on this site and realized his costs were very inflated. I purchased the magnetron for $220. It arrived at my door two days later. Installation was very easy. First, I unplugged the unit. Then, while my wife was making sure it did not fall off the wall bracket, I unscrewed the two mounting screws from the top of the cabinet. I lifted the unit down from the wall and set it on the kitchen counter. The shell needed removed from the microwave which involved about 20 screws. This provided access to the magnetron on top. The magnetron is secured by five screws and a plug. I unplugged it, unscrewed it, and removed the old part. Then, I installed the new magnetron, and tested the microwave to make sure this did the trick. It worked. I put the outer shell back on the microwave and cleaned the microwave. (This is a great opportunity to clean the areas you do not typically see!). I then remounted the unit and plugged it back in. Saved myself a bit of money so I took the family out to dinner and a movie to celebrate. Microwave was in working order for heating up left overs the next day! Thank you!!!

I simply went on line to Part Select, placed my order, made payment, and was astonished to see the package with a new dish sitting on my doorstep the next day.Great service.

The only reason it took over 30 minutes was that the unit is a built in over the stove type installation. The special Philips like screw driver which I purchased was the wrong size. I had to use a small vice grip tool to remove and reinstall these screws. The suggestion to use a butter knife to spread the slot was a good one. The delivery from part select was amazing. We were not without our micro more than a few days

1.ordered the part 2.during wait time for part,i epoxied the broken ear of the door latch bracket back on to the broken part.3.waited 24 hours for epoxy to set,4.installed the repaired part.5.reassembled the microwave and reinstalled in the wall unit.6.days passed and the ordered door latch bracket finally arrived.7.we are using the microwave daily with the repaired door latch bracket,but we will keep the new part in reserve,just in case!JUST CAN NOT DO WITHOUT OUR MICROWAVE!