FIXED 970C85322310 Kenmore Microwave Display only flashes and beeps when door is closed, otherwise blank

[BrocknRoll]

Model Number

970C85322310

Brand

Sears Kenmore

Age

1-5 years

I have an over the range Kenmore microwave model 970C85322310.
The unit appears to still have power because there is an audible beep and '12:00' flashes once quickly when the door is closed.

After watching some YouTube videos and reading some other threads, I have pulled open the front panel and checked the 20 Amp fuse, it is not blown.
I have checked the upper and lower door switches, they appear to conduct when the door is closed, but not when the door is open.
I have checked what I think is the monitor switch, it appears to conduct when the door is open, but not when shut.
I have also checked the two thermal cutoff fuses/switches(?):
- the one on the left which is marked as 120V does conduct;
- the one on the right which is marked as 70V does not conduct.
I pulled the one on the right out thinking it needed to be replaced, but then read in a previous thread here from two and three years ago that this is actually a thermostat that operates the fan and is normally open.
It is marked as G KSD201 70.

Not sure where to go next, buy the KSD201 70 part, keep searching for another issue or look for another microwave.
Any guidance would be appreciated.
thanks
Brock

 

[rickgburton]

Some Canadian model numbers we can't get any information on and that might be the case here. Recheck your model number for me. I can't anything to come up with that one.

conduct when the door is closed, but not when the door is open.......checked what I think is the monitor switch, it appears to conduct when the door is open, but not when shut.

Set your meter on the lowest Ω scale. Always remove at least one wire from the component. The monitor interlock is also called a "deadman" switch. It shorts L1 to Neutral when the door is open. If the switch was bad it would blow the 20 Amp fuse. If the display is blank, no clock, the control board is most likely the cause. Disconnect and reconnect the connectors on the board. If there's a keytail connector, reseat it.

 

[bigbuck]

Rick here is the tech sheet for this microwave if you need it.

 

[rickgburton]

Thanks bb!

 

[SilvertipGrizz]

To fix this I had to take the unit from under the cabinet and remove the microwave cover. What I found was the stakon crimp connectors used to connect the cabinet temperature sensor located on the upper surface of the interior failed. The wire insulation was cooked and the conductor burned off the crimp connector. Closing the door generated enough vibration in the cabinet so the loose wire would touch the terminal for an instant. Trimming back the wire and replacing the slip-on female connectors (which I both crimped and soldered for good measure) corrected the problem. Ours is a Canadian Kenmore model 970C85322310.