JMC9158AAB - Instructions

Removed case,
Discharged HV capacitor and removed cooling fan.
Unscrewed ground end of HV diode and unplugged from HV capacitor.
Installed new diode by reversing the order. In my case, the problem was the magnetron was bad, so I replaced it as well.

Initially we started looking to buy a replacement microwave to replace our 13+ year old built-in microwave. It was a real pain finding a replacement to fit the exact dimensions. So I thought I'd try to find an old KitchenAid microwave. However, I was pleasantly surprised when this site came up on my search. Their website allows me to input the problems and then it showed two possible parts that needed to be replaced. I emailed tech support and asked them which part I needed. They responded very quickly and said I needed to replace the magnetron. I watched a couple YouTube videos and then pulled my microwave apart. It was incredibly easy to pull the outer cover off. The magnetron had 5 screws that needed to be removed and one electrical plug. Took me maybe 10 min to complete the entire repair. It was one of the easiest repairs I've done and so thankful for this site They saved me a ton of money from not buying a new microwave and we now have our microwave working again. In hindsight, I wouldn't hesitate. I'd order the Part now and get it fixed.

Unplug microwave! It's NOT necessary to remove microwave from above stove. Removed two Philips head screws on top front of unit to remove front grille. Removed one screw to remove control panel, letting it hang down. Found inline fuse in cabinet where line cord wires come in. Pulled out blown fuse with thumb and forefinger. Snapped in new fuse, replaced control panel and grille with the three screws. Plugged in the microwave. -Worked great! Good opportunity while grille was off to clean it and replace the charcoal filter inside the cabinet.

Removed the MW from the wall. Took the top screws off the air vent. Then removed the two screws holding on the display. I then moved the display to its side and it revealed the micro switches. I removed the plug in leads from the micro switch one at a time. I did this with all three micro switches only one at a time. I reinstalled everything and plugged it in. No more fans starting when the door is opened.

Removed outer cover

removed lower door switch

installed new switch

Wa La!

well I unplugged the microwave one day prior to working on it. shock precaution smart way to do this job. very easy pullout the screws behind the unit pull off the outer casing. minor screws inside the unit you have to remove a couple things out of the way. unplug the magnetron and remove first gives you more room to work on the side panel to replace the micro switches. I only replaced one the bottom micro switch. only one bad, but since I was in there I clean the bulb and changed the magnetron any ways. I read other reviews and made my choice to do so. it works perfectly now. Thanks PartSelect for having parts.

Unplug the microwave. Remove the Philips head and safety Torx head screws along the bottom of the sides and rear of the microwave which hold the black cover on. Lift the cover up at the rear and slide it backwards to disengage the tabs on the front top. Remove the cover. Discharge the capacitor by shorting the terminals to each other and then ground. Do this with a well insulated object and be aware there may be a pop when you do this. Keep hands, etc. on the insulated part of the object (screwdriver handle, etc). There's a lot of stored energy in that capacitor. I'd advise first checking the diode to make sure its not bad. Replace it if it is. The Magnatron is held in with a couple of screws on the top and sides. Unplug the connector and remove the screws. Remove the Magnatron. Installation is the reverse of removal.

Opened Box and Replaced Part......No Problem!

I went to LG website enter model number and was given a list of parts that need to be replaced with a percentage of which part fails the most. I order micro switch PS3522738 which arrived and PS3529293 was backordered. I installed the one that arrived. The microwave worked briefly. I reordered and waited for both switches to arrive and installed both. The microwave still doesn't work.

Removed some cosmetic panels. Removed the assembly with micro switches. Examined the faulty switch by checking the clicking action of switch. Two others were ok by this method. Replaced the switch with new one. Works fine so far. Thanks to web site and YouTube videos.

Replace (after testing w/ohm meter) diode and locker holder. My door often would not close properly. Microwave let know by saying not shut properly. When disassembled found the top screw mount was hollowed out resulting in it moving on occasion when you close door. First remove casing (special safety torx head) needed for rear screws. Onc e removed all parts available to view or work on. Diode is on the capacitor so caution is needed when removing. Serious shock hazard if touched. Use insulated pliers to remove from capacitor and a phillips on the ground. Test with ohm meter Should have resistance on way and non the opposite. Replaced mine bad. Next the holder 2 phillips screws and its yours. Unplug each switch and remove. Take note to what wires go to what switch and what switch mounts where. Mine had 3 switches. Removed from old holder and put in new. Screwed holder back in place and left scrws loose till re wired. Once wired set the holder by lightly tighting the screws. Try the door till it seats properly ensuring that all 3 switches are working properly. If so thighten screws. If all seems to work as advertised, safely plug in and test unit if heats up un plug and put cover back on micro. Your all set. Happy heating.

The power on the microwave went completely out when I went to use it, but there was no power failure for the house or neighborhood. We removed the microwave from above the oven. Took out the screws on the sides and back of the microwave and slid the top back. The line fuse was located on top unobstructed, NOT behind the button panel like some microwave models. As the appliance is over 20 years old the line fuse was quite old. It was really hard to pry it out of its holder and actually broke. I used a vacuum to suck up the dust and glass and it was easier to get out the ends once the middle broke. Popped the new line fuse in, slid the top back on, put in the screws and put the microwave back in its compartment above the stove. Good as new!! We were about to spend money on a new microwave, but thankfully I came across this site. So happy I did!!

This repair was really easy. The part that took the most time was taking it down from it's compartment above the oven and putting it back up there once repaired.

Pulled unit out, pried the bottom plate off the unit. Mine was not screwed in, but designed to be pried off, and then replaced. That was a surprise, but not very difficult. Unscrewed the motor, unplugged the electric connection, replaced it with new part . Replaced the bottom plate and tested the machine.

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.