Samurai Appliance Repair Man's Blog

This Public Service Announcement is brought to you by Brother PDuff:

I'm reminded of one time, a fellow tech and myself were at the shop.  He was working on a large countertop microwave and I was down the hall in the front office.  We could see each other and were carrying on a conversation, I forget about what.  I'm absolutely positive he had a few fillings in his mouth because as he was looking and talking to me his hand must have touched the high voltage diode or capacitor, discharging it.  I kid you not sparks flew out of his open mouth!  Being the trained and responsible guy I am I immediately fell to the floor, laughing my ass off.  I eventually recovered and asked him if was ok and he said yes, just scared the hell out of him.  I said, "Man, did you see sparks fly out of your mouth?"  He said no, he must have missed that.  Needless to say we both found new respect for microwaves and the awesome, dangerous, and sometimes hilarious power of the high voltage capacitor.

To learn more about your microwave oven or to buy parts, click here.


Source: Im DUMB and need help on Kitchenaid Microwave khms2040wss-0

yes it is the transformer

the noise is a loose winding and will never stop the microwave from working or make it unsafe in any way

if you replace the transformer the noise will go away

Replacement transformer for your GE microwave oven.


To learn more about your microwave oven or to order parts, click here.


Source: GE MICROWAVE

The deal here is that one of the torsion bars is broken.  Even though it's usually only one that breaks, you want to replace both as a set.  For the stainless steel models, Grand Master Reg hooks up with the needed parts and diagram:

4451009 Black / White / Biscuit models
4452396 Stainless model (stronger tension)
(original SS models may have had one of each)

click on picture


click on picture

Source: Microwave Door Flopping Down, What Parts?

Most microwave ovens have three safety microswitches in the door latch assembly.  The diagram below is typical:




These microswitches aren't the most robust switches ever made and can be down right squirrely.  They may test good one minute and then look bad the next.  When a switch looks flakey like that, trust your meter and just replace it.  Chief jumptrout's experience with this is typical:

Had a strange occurrence today on a microwave call.
The lower microswitch that activates closed when the door is closed was the problem.
With the switch in place and the door closed,there was no continuity in the switch.
I removed the switch and did a double test of the switch to verify a bad switch.
When the button was pressed,the switch made momentary continuity.
When completely depressed the switch broke continuity.
If you backed off on the pressure on the button,continuity resumed.
Has anyone seen a situation where this has happened?

Yep i have had that before a few times...nice catch. That can be easy to miss if your not diligent.

Source: Weird microswitch

A powerful troubleshooting technique when working on microwave oven that won't heat is to split the problem in half to determine if the problem is coming form the low voltage side or the high voltage side.  A test cord can be a very useful troubleshooting tool because it allows you to so just that.  Sublime Master Chat_In_RI enlightens us on this technique:

Why can't you make a test cord to power the M/W?

No model number here, but a test cord to the primary side of x-fmr to by-pass door switches, relays, etc...  and if your diode and cap check out OK, narrows it down to the mag if no heat.

Source: GE Double Oven Microwave not heating