MS85MN (HBLEGSS) LG Range - Instructions

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.

I replaced the whole component with all three switches in it even though only one switch was bad . Taking out one switch out of the holder unit would probably have damaged the unit that was holding the switches. Easy install and it works great again .

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!!

diagnosed defective 'door-shut switch' in the switch holder assembly. rather than replace switch, replaced entire locker holder assembly which made for a very simple and easy repair...not to mention very inexpensive.

Not knowing which of the switches to replace I ordered all three in the assembly. Replacing the full assembly was easy, first unplug the microwave. Then remove the top cover to access the screws that hold the control panel in place and let the control panel hang. There are two screws that hold the assembly in place - remove those. I used needle nose pliers to pull the wires off of the switches and immediately put the wires on to the new assembly so there was no confusion on what wire went where. Place the assembly back in position, replace the two screws to hold it in, put control panel in place and secure screws. Replace top cover and plug in.

picked up turntable plate (glass), removed broken part, placed new part
in position and replaced the glass plate.
less than one minute

Read the troubleshooting section on this site. Figured it was an interlock problem because the food was not getting hot (magentron not turning on) and the carousel was not turning. Did not think both the carousel motor and magnetron failed at same time, thus indicated an interlock problem. The interlock switches are actuated by the door latch. Replaced the assembly locker piece with all three switches (only a $20 dollar part) and microwave was fully operational again. Wife and kids think I am a hero.

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.

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.

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

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

Remove the rear casing of the microwave using both a Phillips head screw driver. The lower rear screws require a star shaped bit with a hole in the middle (security bit). Once the rear casing is removed, it is very easy to access and replace the bulb. But the bulb sent was NOT identical to the original which has a straight fitting into the receptacle. The one sent had a fitting with a 90 degree. The bulb did not quite fit in place, but I secured it with some black electrical tape.

Needed to raise the part to match the ring. I used peanut butter to hold plastic shim while replacing to hold it in place. Built in Oct. 2009.

just lift the glass turntable off and take the ring out and put the new in and put the glass back.

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.