MT1145SLB (AB1EWRP) LG Range - Overview

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 l ... Read more eft 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 dir ... Read more ections 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!!

Removed each switch (3) and checked them with multi-meter; got intermittent readings on two of the three. Also broke of a piece of the frame that holds the switches trying to remove them (old, exposed to heat and moisture over the years caused the plastic to become brittle and the wiring connectors were also hard to disconnect probably be ... Read more cause of heat and moisture over the years).
Went to PartSelect web site and discovered the three switches and frame were bundled in to one part number, 43501A. So, I called and spoke with a very knowledgeable technician and she explained why plus helped me order the part over the phone. When I received the part, the switches were already mounted in the frame and the frame was modified compared to the OEM frame. As I began to remove the old frame, I discovered why the new frame was modified. It was as if PartSelect had done many of these door interlock repairs and they knew exactly where and how to modify the frame and communicated this with the manufacturer, because the new frame installation was very easy, there was nothing hard about installing the new frame with the switches already in place. I then reconnected the wiring to the switches and tested the microwave and it works fine now, Problem solved, Thanks PartSelect.com