I have several questions, but here is the first one what is a magnetron?
Stupid question I know! There is RF frequency statement by the model #
that
says RF 2450MHz; will this frequency interfere with my 2.4GHz wireless
router?



A magnetron is the vacuum tube which generates the microwave energy. 2.4 GHz
would certainly interfere if it were not contained but microwaves are
usually shielded well enough that this isn't a problem. All consumer
microwave ovens run at this frequency.



What is causing the popping, crackling? If I was not in-depth enough
please
let me know.



The paint inside the cavity has been damaged and it's now arcing just as it
would if you stuck a fork in there. Sometimes this can be repaired if you
clean it very well, sand off any oxidation and then touch it up with
microwave oven cavity paint. You'd want to check the condition of the
waveguide though to make sure it isn't damaged. Microwaves ovens are simple,
but they can also be deadly to work on, please read the repair FAQ before
poking around in there.


I will also scan the service sheet in a day or two in PDF format and post
it
with the same subject heading.



Thanks for your time that it took to read through my post.



Mike L.