JMC8127DDB Jenn-Air Microwave - Instructions

The instructions on the website were incredibly easy and I saved myself a lot of headache by using this site.

-it was built in unit - so I needed to pull the decorative grill from around the outside to remove it from the wall
- removing the back of the case involved removing phillips head screws from along the side and back of the unit. the only issue I encountered on removing screws was the fact that the "torx / star" screws could not be fit with the wrench that I had (they had a pin in the center that would not allow the wrench to fit into the star). However, a pair of pliers was handy and they were removed just easily.
- I had ordered both the high voltage diode and magnetron because I didn't know which item was the problem. I grounded the diode with two screwdrivers while wearing rubber gloves to be safe. the warnings on this did the trick as it was the only scary part of the operation.
- the diode was a little hard to spot looking at the schematics, but is is found on the lower right corner of the right side of the panel and easily pulled out and replaced. I tried the microwave again to see if it worked...and it did not. So I confirmed that the magnetron was the issue.
- removing the screws for the magnetron and putting in the replacement was a dead easy and I tried the microwave again before putting cover back on. Worked like a charm. Super easy!

removed a dozen screws-discarded large cap-replaced diode-replaced a dozen screws(took longer to replace them than remove for some unknown reason). Microwave now works(wife happy).

Took microwave out of builtin cabinet with 4 screws.
Put microwave on center island and removed cover.
Tested interlock switch with volt meter and it appeared ok so I put my kit back in box and sent back.
Took out magnetron unit and replace with new part.
Put cover back on and test.
All is working and installed back in cabinet. Two weeks later all still working great.

ordered a new tray

There were two hard parts for me to work through.

The first was breaking off the two screws that need a special head screwdriver to remove. None of my special special head screwdrivers worked (I have a few), so I used a hammer to force them off.

The second hardest part for me was finding the correct replacement bulb on-line. My Amana Microwave is a combo Microwave/Convection type, and it's a strange little bulb - almost tube like.

Once I did find the right bulb on this PartSelect.com website it was a breeze. The part was delivered in just a couple of days (even during this Covid-19 pandemic). Once I had the replacement bulb in hand it barely took 5 minutes to install.

Thanks PartSelect!!

I had to unmount the over-the-range microwave oven to be able to gain access to the interior of the oven. Complicating removal (and re-installation) was the fact that there is a "pot-filler" faucet installed directly underneath the oven. In retrospect, I should've removed the faucet before doing the repair, but "c'est la vie."

After I got the microwave down, removing the case was also "interesting." I get bonus points for the fact that the previous owner must've had to replace the same diode before - and then re-assembled the microwave case incorrectly - thereby adding to the confusion (BTW, the service manual that I found online said nothing about how to remove the oven's case).

To remove the case, undo all the screws holding it on, and then rotate the case upwards from the back while also pulling the case backwards. There are crimped folds on the inside of the case that mate with the back edges of the front of the oven's chassis, and these folds have to be unclipped from the chassis in order to remove the case.

Replacing the diode itself was the easiest part of the job. The two connectors on the diode are of different types, making it impossible to install the diode with the wrong polarity.

BTW, the diode that had failed was not an OEM diode; I suspect it was a generic component that had been installed by a repairman sometime between 2004-2008 (when our home's original owners still owned the home). On the other hand, the new diode from PartSelect is an OEM part (it came packaged in a sealed Whirlpool bag).

The fact that the oven had stopped heating indicated that it was either the high-voltage diode or the magnetron that had failed. Since a replacement diode costs ~ 1/10th as much as a replacement magnetron, I figured it made sense to replace the cheaper part first. Fortunately, this fixed the problem.

One last thing: I tried testing both the old and new diodes for conductivity and polarity using my volt-ohm meter (VOM), but I was unable to get either diode to "turn on," even though my VOM is powered by a 9-v battery, and I used the 2-Mohm range setting. I guess the test voltage of my el-cheapo VOM isn't high enough to exceed the diode's threshold voltage, (even though I have successfully used this same VOM to test low-voltage diodes).

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

Required that i remove the built in frame and mounting. Required tamper proof socket to remove housing. I removed the old bulb and simply replaced and reverse installed the cabinet.

Dropped the microwave bottom cover removed motor and installed new one. Prior to putting bottom cover back on took time to give it a good cleaning.

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.

you will a security socket T20. this unit was installed over oven, remove trim cover,remove screws holding unit in place,I used a helper to get the unit out, once out you have to remove all the screws holding the cover on,on two of the corners they use a security hex screw so you need a special socket for that. remove the door latch switch,take your time or you will break tab holding switch in. ask me how I know.but super glued broke piece in place and plugged wire back in.the new latch may have a second pin but look at old one and plug wires in the same way.the light bulb does not screw out so I had to purchase the entire unit.total cost under a $100.00 to do repair.

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.

You have to remove the cover which in my case was a little more difficult because the unit is wall mounted and has a frame around it. That was the hard part. Once the mounting frame was removed, you can remove the cover and the light bulb is on the top right side of the unit. One screw removes it and the new one pops right in. Put the case back on reinstall it in the wall and voila...piece of cake.

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.

hardest part was taking the microwave down off of the wall to gain access to the diode. Thought if was the transformer but ended up being just a blown diode. remove and replace and bench test. that part took 15 minutes . moral of the story don't boil water under the side of the microwave that holds the electric components.