JNM7196DF1BB GE Microwave - When using for several minutes it appears it lost power

[brmommy]

Model Number

JNM7196DF1BB

Brand

GE

Age

6-10 years

A few weeks ago I used one of theses glass microwave popcorn poppers. I didn't really notice at the time but the next time I went to use the microwave it was asking for the time to be set.I didn't remember the electric flashing off so thought it was strange. Another few days went by without noticing anything strange. I again used that popper and noticed when I took it out it asked for the time to be set. Started to wonder. The next (and last) time I used that popper I opened the door to take it out and the power was off to the microwave. The glass tray was EXTREMELY hot to the touch. I left the door open and after a while it cooled off and the microwave seemed to work again. I decided not to use the popper again. I don't know if it was coincidence or not. After watching it the last few weeks it seems to work fine when re-heating something for 2 or 3 minutes. If I try to cook a frozen microwave dinner or anything that requires 5 or more minutes it is shutting off and the glass plate is very hot. It eventually cools down and will heat the short 2-3 minute cycles fine.

Any idea what might be going on? It's only been 3 years since I replaced the control panel in it. I've now heard others say those popcorn poppers ruined their microwaves but none say what was ruined. Is it something I can replace?

 

[brmommy]

No responses???

I'm wondering from reading other posts and the fact that the glass plate is getting so hot that maybe the magnetron is over heating. Anyone have any feedback at all?

 

[Jake]

Hi,

I don't have any Microwave experience, hopefully @Wx4usa can assist you.

 

[Wx4usa]

When I see the turntable getting hot, and it is clean, I suspect the stirrer may have failed, the magnetron, or magnetron waveguide may be damaged or the magnetron cooling fan may have failed. It is not safe to use until rectified. The stirrer is a small metal set of blades, (circled on left of image) usually in the ceiling. These blades spin either by a motor or airflow. Your model has an airflow driven stirrer. It could be restricted or not have the airflow it needs. The magnetron cooling fan may be failing or failed. When the microwave power turned off, I believe that may have been the magnetron thermal cutoff TCO. It will kill power to the entire microwave even the control. The control will reset just like being unplugged or after a power failure. The microwave will then reset when it is cooled off. I would first make sure the magnetron fan is running. It is on the right side of the picture attached. The stirrer is on the left. I circled both in yellow. If the fan is not running the magnetron will get too hot and shut down the microwave. I believe the airflow from that fan turns the stirrer, not the vent fan.

 

[Jake]

Thanks @Wx4usa for helping.

 

[bigbuck]

Uses this tech sheet:

https://f01.justanswer.com/smitty1486/a54f5320-f243-4e6f-bd30-2a4e23245388_JVM7195SFSS+Service+Manual.pdf