LRMM1430SB LG - Instructions

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.

Overall repair quite simple. Removed screws from the sides and rear of the microwave, then removed cover. Next, removed only the screws to separate the bottom cover. Removed the one screw in the AC Synchronous motor to remove the motor (had to use small screwdriver through a vent slot in the bottom to remove the screw). Unplugged and removed motor. Installation is the reverse of removal. Note: on the back of my appliance were 4 torx screws with a tamperproof pin in the center. I used the rotary tool to grind out the pins so I could use a regular torx bit instead of ordering specialty bits.

Eight screws off the bottom exposed the cover plate. Easily found the motor location the looked up the item number and verified data and ordered the part. Replaced the motor, tightened the screws and flipped it upright. Plugged it in and the lights came on. Set a time pushed start and smiled! The eagle had landed!!!!

Ordered the switches from Partselect, arrive in two days. Had trouble removing the plastic connectors from the old switch terminals, one of the plastic protectors broke, but was able to reuse it. It took a little figuring out how to remove the existing switches. Must push in a tab and rotate the switch on a little pin, then remove. Must be careful not to break the plastic tabs holding the switches in place. Replaced all (3) switches at the same time. All in all it was pretty easy.

I removed the outer cover of the microwave and removed the bottom palte to access the small motor. i unplugged the old motor from teh wiring connector, removed (1) screw and motor came out. I reversed the proceedure with the new motor and it was finished.It was a piece of cake.

Unplug.Take off the external cowling from the back of the unit by removing the torx security screws. Tip: instead use a thin screwdriver blade to unscrew the torx screws, or knock out the center pins of these screws. Remove the bottom panel. The replacement motor is attached with one phillips screw, re-attach wires to motor - polarity doesn't matter. Re-assemble and you're finished.

Problem was due to a faulty door switch. Replaced with a new switch and the microwave now works fine! Only thing that was tricky was that LG uses the hex screws with a peg in the middle to keep the microwave cover on. Had to use a small screwdriver and pliers (on the screwdriver) to unscrew the screws.

Pried cover off bottom-center of microwave. It seems to be either glued or lightly tack welded. Removed 2 small Phillips screws to remove motor. Disconnected electric feed by hand. Don't let go of electric wire or small screws. They will be hard to retrieve from behind the rest of the metal base. Reverse process to install new motor. Didn't try to put small cover back on.