JMC9158AAB - Instructions

ordered a new tray

1. Order correct light bulb for unit and have it with you before removing old lightbulb.
My Microwave is built into cabinet.
2. Disconnect power (Either turn breaker off or unplug unit from wall)
3. Remove face cover on cabinet. (4 Phillips head screws)
I was able to reach in the opening in the cabinet and unplug from the wall.
4. Remove Phillip head screws holding microwave in cabinet.
5. Remove microwave from cabinet.
6. Remove Phillip head screws and torx screws holding outside cover on the back of unit and the side (1 on right side) and then remove cover.
Light bulb is on the top front right side.
7. Remove 1 philip head screw holding light bulb and unplug quick connector wires.
8. Plug quick connector into new light bulb same way it came out and place new light bulb in place and put the 1 philips head screw holding it back in place.
9. Put cover back on and all the screws. Temporary plug the unit in to test light bulb works before securing it back into cabinet.
10. Reverse order 5,4,Plug unit in wall before putting the face back on.
Done.

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!

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

Take cover off microwave. Check door switches to determine which one was faulty.Remove and replace faulty switch.

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.

remove the shroud. 2 types of screws. Philips and 2 specialty star screws. Then remove the light socket. 1 Philips screw. replace the socket and bulb. The bulb and socket are 1 piece. Replace the shroud.

Did an online search for repairs and found PartSelect. Simple to order the part and had it installed myself less than a week later. Thank you!!

I want to preface this review by stating that I do some DIY from YouTube, but have no experience in electronic repair. The microwave is over the stove with the extendavent. First I unplugged the microwave, removed the vent and started to unscrew the microwave from the mount. I used a power drill to speed things up. I was able to remove the microwave on my own. I unscrewed the lid on the microwave and took the lid off and there is the magnetron. I opened up needle nose pliers to have each end touch the terminals of the capacitor (holds the power, Dangerous). I made sure to keep my hands on the rubber handles and avoid touching the metal part of the pliers. I used the pliers to remove the plug of the capacitor to the magnetron as well. The magnetron has 4 screws (2 top, 2 bottom). There is a magnet that can hold the screws to keep from falling but I’d still recommend a screwdriver with a magnet on the end. The magnetron has another set of wires connected by a metal bracket like a holder, not really connecting any wiring to the magnetron itself. I had to unscrew 1 screw to removed that. Adding everything back on was easy, same steps back. I plugged in the microwave and tested a cup of water before I mounted it back above the stove. Voila! I did need my wife’s help to hold the microwave on the hinge while screwing into the mount. It doesn’t take a lot of muscle for the help. $85 for the part and ~40 mins to fix a $400 microwave!

i unplugged the unit,unscrewed the outer shell so that all the wiring and internal components were visible.starting at the first of three micro switches i removed the slip on terminals installed the alligator clips too the wires so the switch would now be bypassed.i made sure the wires and clips were not touching anything plugged unit in and it worked.i then installed the new switch and closed up the outer shell

I verified I had 120 volts going into transformer when the microwave was supposed to be running. The capacitor and HV diode both tested good. Be sure to discharge the capacitor before working in this area. This isolated trouble to either the transformer or magnetron. The windings of the transformer measured good. So ordered a magnetron. It was very easy to swap. There were 4 screws and one connector. This fixed our microwave.

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.

I looked up my problem on the internet and found a very helpful video. Microwave on video was different brand but the internals and methods were very much the same. The video made it simple and easy to fix. Found the replacement switch on the LG parts site and ordered. Two different switch types. One with red switch, the other green. Part was $7.28. Saved a bundle in service costs. Here is the repair video.

https://www.youtube.com/watch?reload=9&v=_AglBJoHgDs