How to Troubleshoot & Replace Bosch AP4513044 / 00648909 Door Lock

It looked at first like failure of the middle of the three switches that sense the open/close status of the door. Replacing this restored function for a day or so, until the problem returned. I noticed that slight wiggling of the door could close and open this switch. Looking closely at the "lock" it appeared that the ramp that the door catches slid up were worn at the inside edge. The replacement part confirmed that the end of this ramp was worn. This apparently causes the sequence of switch closures to sometimes go wrong. It has only been a few days, but looks like replacing this part did the job. Why an expensive microwave would contain a part made of inadequate plastic, leading to failure in 5 years, is a good question. 

Microwave would trip the breaker when I would press start. So I looked on Google and found on Youtube which indicated it could be a door switch. "IMPORTANT I AM AN ELECTRICAL DESIGNER/ENGINEER THERE IS A CAPACITOR THAT HOLDS ELECTRIC ENERGY EVEN WHEN UNPLUGGED DO NOT DO THIS WORK UNLESS YOU KNOW WHAT YOU ARE DOING TO REMOVE THIS ELECTRIC ENERGY SAFELY" I took apart the microwave and behind the touch panel of the microwave was the wiring sheet. There are (2) switches on the door. I took a meter and check for continuity of the switches with door open and closed. What I saw in youtube was correct, it was the middle switch which is the door monitor. The bracket that these switches mount in seemed to have a broken clip on one of the switches. So I ordered all (3) new switches and the bracket with spare fuse. When parts came in, I replaced everything verified the switches worked correctly with my meter again then did a test before remounting. It worked! $50 buck vs 200+ for a service guy or more to replace microwave. 

I changed the filter module and the 3 door micro switches and their holder to be safe. 

The middle Door Switch was actually bad. Replaced all 3 switches any way's. Going to order another set of switches and bracket just for a spare. Service was fast and the FedEx delivery. 

I replaced the door switches and the holder for the switches. I probably did not need all of the switches, however I wanted to rebuild the entire assembly so as I would not have to replace them one at a time. You could replace just the switch that is bad, you would need to take it apart and test each switch to determine which one is bad, then order that switch, so you would need to take it apart twice. Watched a video on YouTube on the replacement of the switches, the parts were all correct from AppliancePartsPros.com Thank you. 

I installed a replacement middle switch. There are three of them and one of them was shot. A simple multimeter or continuity checker will verify. My microwave had the chart for diagnosing wedged inside, next to the control panel. There are numerous videos available online that will help out if you need it. These switches are not very well constructed and within a month the new switch failed. Partspros sent me a replacement. They are not very expensive and shipping was about twice the cost. I learned my lesson and ordered a few extras to have on hand for when it goes out the next time.