LRMM1430SW LG - Instructions

My 8 year old daughter cleaned the inside of the microwave with enough water to rival a tsunami. Resulted in a clean microwave with a fried out motor that no longer revolved. Part came quickly. Took cover and bottom off to get to the part. One screw held it on and a plug. Removed those, put on new part and she was good to go. No trip to home depot today.

Unplug the unit before servicing. Need phillips screwdriver. Open door. Use step ladder to access and remove 2 small screws from top of the room air diffuser at top of unit. Slide diffuser slightly to the left to align the diffuser's plastic tab on the left side to rotate toward you. (The wires for the front control panel are at the far left side of this difuser, but difuser is slotted for easy removal). Once the difuser is removed you will see 1 screw at the top that secures the pannel cover on the left side of the unit. Remove screw and slide this panel slightly up and out. This exposes the plastic frame that holds the upper and lower door switches. To locate the door switches and observe how they work, close and open the door and watch the door (bayonets) open and close the micro switches. Do the (red) buttons on top of the switches move up and down when the door bayonets push and release? If the buttons do not "pop" up when opened the switch is defective. The switch frame is secured with 2 screws. Remove screws and rotate the unit out for easy access to the micro switch(s). The internal (spring?) on my unit that is suposed to allow the red (visible) button on top of the switch to "pop" up when the door is opened was broken. Carefully pry the switch outward while being careful to lift the plastic holder-piece that holds the switch in place. Be careful, there is a small pin on the frame, so rotate the switch OUT toward you while lifting (carefully) the plastic holder-piece (you will see it on top of the switch). You can use an ohm meter to test the continuity of the switches. But if the buttons don't "pop" they are defective. Replace switch and reassemble.

Watched a couple of repair videos on Youtube by searching for the model number. Found out what to do in order not to get shocked by the powerful capacitor.
Ordered the two switches (To be sure, I could have ordered a third switch as suggested in the videos.)
Bought a tamper-proof star bit to get the cover off. Followed the directions to replace the switches. - I broke the harness and had to use some super glue, but it's all good. I should have removed the harness instead of trying to get a switch out while it was still in place.
It's all back together, and the wife is happy!!

Note: also had to replace turntable. Removed top cover using secure driver set. Placed microwave on it's front, using a soft towel. Removed edge screws from bottom plate (leaving 4 screws in center attached to heavy transformer). Separated bottom plate from body of microwave (leaving transformer wires still attached) exposing Synchronous motor. Removed two screws holding motor and electrical plug. Swapped new motor in its place. Re-attached bottom plate with its screws. Placed microwave onto it normal position. Re-attached top cover with its secure screws. Installed new turntable inside.

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.

Remove 2 Philips Head screws on left side of microwave. Remove 3 Philips Head screws from bottom rear of microwave. Remove 4 security screws from back of microwave (holding the cover to frame). These are the security type tips that are like a Torx bit, but need to be hollow in middle to accommodate pin in center of screw. Then back plate of microwave with heavy transformer still attached slides up and away. The wires aren't long enough to allow it to rest flat on the bench, but weight is low so it's easy to hold it upright while removing the motor unit. Separate connector from motor (simple) Remove motor by unscrewing 1 phillips head screw and rotating counter-clockwise a tiny bit. Remove Motor. Reverse steps to re-assemble. Note that there are a series of tabs at the bottom of the back cover that fit into holes in the baseplate of microwave. It can be a little tricky to line them up with the weight of the transformer, but it's not too bad. Once lined up, it drops in nicely and all the various screw holes line up. The microwave is a bad cooker when the plate doesn't spin. This simple and inexpensive fix saved me from having to buy a whole new oven.

Replaced entire door latch assembly with the three micro switches. Easier to replace entire latch assembly as individual switches do not remove easily from latch assembly. Had trouble removing front panel assembly. Parts ordered solved this problem.

Turned the microwave on its side. (Recommend turning it on its top. i had to fish the wire connection back to the center after it dropped away from the motor.) There is a spot under the rotation motor where an access port was stamped in the tin but not cut out. Used the small side cutter to complete the cut where tin had been left between holes. I unplugged the wires, removed the old motor by removing one screw, and installed the new one by reusing the same screw. The motor must have a reduction gear inside the case. The motor coil tested good, about 128 ohms, but it acted like there was a stripped gear inside. I wasn't interested enough to try to open the motor and confirm.

Had to go to the garage and get a small sheet metal screw to close the new trap door.

The "new" motor had scratches on it, made me wonder if it was really new, but it works fine and will probably outlast me.

Removed micro bottom - 5 screws. One screw on the motor and a clip. Reversed the sequence, turned it on and watched it turn.

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.

your part and YouTube video (which just happened to be my microwave)
changed bottom microswitch...done and dusted in 20 minutes...your $14 part 3B73362F saved $350!!!

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

Easy, and the microwave still doesn't work.

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

Take off cover then the bottom. Transformer is on the bottom plate and wires won't let it come all the way off, too many wires to pull off so will have to position the bottom plate so you can get to the motor. Remove 1 screw on motor and remove motor. Install new motor connect wires replace bottom plate, replace cover. All done (hope & pray it works ok) mine worked perfect. Hope this helps.