Panasonic Microwave Oven - Burnt Connectors on Mystery Part

[Number_35]

Earlier today our microwave oven quit working suddenly.

A few months ago it blew the fuse, which was caused by a microswitch going bad. Replaced the fuse and the bad microswitch (and its still-functioning partner), and it worked well until today.

Checked for power at the receptacle - yes.

Took the cover off to do some troubleshooting. The fuse was good, and the microswitches checked out fine. (Tested them with an ohmmeter.)

Checked for power in on the power cable - yes.

Then noticed the charred connectors to the little round component.

I plan to re-terminate the wires, but would also like to test the unknown component, and replace it if necessary.

Does anyone know what it is?

Thanks in advance.

 

[spasm3]

Looks like a thermal switch/circuit breaker to me.

 

[Number_35]

Looks like a thermal switch/circuit breaker to me.

Could be - I just ohmed it out, and it's a dead short.

Maybe I can get away with just re-terminating the connections to it.

 

[brianl703]

That is a thermal switch. It is probably normally closed and opens the circuit when it gets too hot.

You can get a replacement online. The trip temperature should be written on it.

 

[dishdude]

I think your magnetron is shot. Time for a new microwave.

 

[Gyro Gearloose]

The terminals are apparently the point in that circuit with the most electrical resistance so they got the hottest and melted. Something is drawing too much current to burn them up like that. I would guess the device is a thermal switch to shut the power off should your food happen to achieve ignition.

 

[MasterSolenoid]

Good websites for troubleshooting and ordering parts.

https://www.appliancepartspros.com/
and
https://www.applianceaid.com/index.php
and
https://www.applianceblog.com/mainforums/

 

[Number_35]

I think your magnetron is shot. Time for a new microwave.

The terminals are apparently the point in that circuit with the most electrical resistance so they got the hottest and melted. Something is drawing too much current to burn them up like that. I would guess the device is a thermal switch to shut the power off should your food happen to achieve ignition.

So, dishdude and Gyro Gearloose, putting this together, I'm hearing that the failure of those terminals is a symptom of excessive current, and that the cause of that is something significant like the magnetron.

Rats, I really like this microwave oven, but perhaps it's time ...

 

[MasterSolenoid]

Looks like this person had the same problem / check out his photos.
I'll let you read the responses.
https://www.applianceblog.com/mainf...th-burnt-connectors-on-thermal-cutoffs.83157/