ACM1580AC - Instructions

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.

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.

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).

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!!

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.

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.

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

Frist removed locking clip,lifted door,removed damaged part an replaced door.

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!

Used a Motor cycle Jack to remove both unites combined. Removed side panels exposing internal working parts. Removed nonworking Magnetron and replaced it with new Magnetron. The process was completed in about 1 hour.

Initial failure of over range microwave Aug 3rd. Control Panel worked but no heat. Took to local LG authoriaed local repair place. They fixed it quickly and we re-installed it. Worked fine for 2 months then had similar failure again. Agaim took to same authorized repairer. They kept unit for 3 months but finally concluded theu could not fix it and suggested we contact LG for a partial refund. When they tested the unit during re-assembly in my presence, there was a blue flash and the fuse blew. Since we had built a custom tile mural back splash around this unit, I brought it home, ordered a number of time delay fuses new capacitor and two new high voltage diodes. However, using my Fluke DMM, I checked the existing capacitor and high voltage diode and they checked OK so I just replaced the time delay fuse. The high voltage transformer leads had 2 possible ways to connect to capacitor and diode. Tried one way, plugged unit in and turned it on, and immediatly blew the fuse. Replaced the fuse and reversed the high voltage transformer connections,amd turned unit pn, and it worked perfectly. Since we had experienced several power failures during the time of the original failure, the repairer concluded that power spikes might be at fault, so I also purchased a TrippLite ISOBAR4ULTRA 3300 Joule surge protector between wall outlet and microwave, and re-installed over range. It has worked perfectly since.

unplug the unit then pull down , lot of screws are on top. open the cover . you could see the parts that need to replace on the right hand side (heavy side). disconnect wires then test the parts that need to replace by a tester to make sure that it's really broke .then unscrew part and replace .