Bosch 00648909 Door Lock OEM Part

Similar to other stories on here, the microwave was repeatedly tripping the circuit breaker, usually when opening the door. Plugged microwave into a different outlet/circuit, and problem traveled to that breaker, so definitely issue within the appliance. Turned out to be door interlock switch. This model has 3 switches: 2 x AP4512903 (00617228, the Primary and Secondary interlock switches) and 1 x AP4512904 (00617229, the Monitor switch). It was only the Monitor switch that was defective, but I went ahead and replaced all of them, as well as the plastic Door Lock (AP4513044) which was developing some groove wear after 7 years of use (makes the door wobble a bit over time). For good measure I also replaced the plastic Lever (AP5263819, aka 00621573; this snaps inside the door lock and controls the bottom switch’s plunger). So I essentially replaced the entire Door Lock assembly, for about $40. Took about half an hour (I took my time) and a Philips screwdriver. Pro tip: Take close-up photographs so you know where all of the wires from the control panel go. There was a helpful wiring and troubleshooting diagram folded up and tucked inside the control panel from the factory (nice surprise). Testing notes: The top microswitch 00617228 should measure open (no continuity) from terminal to terminal until the plunger is pressed. The middle switch 00617229 should measure CLOSED (with continuity) from terminal to terminal until the plunger is pressed. The bottom switch 00617230 should measure open (no continuity) from terminal to terminal until the plunger is pressed. Two screws hold the Vent Hood piece on; take that off to reveal one screw holding Control Panel in place. Remove that (carefully, don't yank any wires), then two screws hold the entire Door Lock assembly in place. Fairly easy to wiggle out; careful not to disturb the metal microwave shroud behind it. Overall, a fairly easy repair. Very happy with the results; working like a champ again. Super speedy shipping of the parts!

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.