Charlie Bress wrote:

This is a 10 or 12 year old Panasonic micro.

In the middle of heating several different things sequentially it suddenly
quit working.

But not entirely. The clock worked and the light worked. The timer counted
down as usual but there was no heating and the turntable didn't rotate.
While I was contemplating replacing it, the wife said she slammed the door
and it started working again.

Maybe some thing was loose. I pulled the cover and did a visual inspection
and everything looked tight and in place.

Is this behavior indicative of a microswitch not getting activated?

Perhaps a bad switch or the interlock parts have become worn. The switches
look replaceable, the plastic parts of the latching and interlock functions
were probably made for that particular model and are unique.

Charlie

Yes, the door interlock switches on most microwaves have two problems
generally. The first is that they generally use cheap switches, so when
you replace it try to get a quality switch (Cherry, or other good
manuf.) to replace it. The second problem is that people typically just
yank the door open without first pressing the stop button on the
microwave.

When you yank the door open while the microwave is running the interlock
switch has to interrupt the sizable operating current feeding the
magnetron power supply which puts a lot of wear on the switch. If you
press the stop button first, the power is switched off by the control
which is far more capable of this switching duty since that's what it
does for lower power levels as well and there is no wear on the already
mediocre door switch.

Replace the $5 door switch and you're likely to get another decade or
more of reliable service.

Pete C.