Microwave died and started spewing smoke

You should be able to get a cleaner spray suitable for use in microwaves. Give the insides a good spray and a good clean, it should take it away. Make certain there is no burnt deposits anywhere.

Seems to me that your magnetron is a goner, check also the antenna shield, cover inside the oven cavity and replace both, you may need to clean and repaint burn surfaces inside oven cavity.

new ovens do have a certian amount of "burn in" to do when there new best to heat up and cool off oven several times before actuall food use to remove any construction solvents and "cure" all the materials inside

also ck to make sure you removed all the shipping packing sometimes this gets left inside by accedent and smells something horrible when heated ( caution :: Foam degrades to cyanide deadly gas when heated!!!!)

magnetrons work only when the unit is cooking
it smells like an insulation from overheating wire so could be a fuse and failing transformer
take it in for a proper diagnosis and quote but if it is over 2 years old the cost to repair could be more than a replacement unit

its also in the ventilation. cover need to come off and basically needs to come apart. completely.

the smoke probably came from the heated food. try using it next time with different kind of foods and also try it to the same kind of food that produces smoke but observe carefully what will happen.

The magnetron (the part that heats the food) may be ready to burn out. If you smell the burning, you should then unplug the microwave, open it up and see if you can determine for sure that it is coming from that part. Unfortunately even if I am right, it is almost more cost effective to just replace the microwave rather than replace that part. You can run this microwave till it dies if you want, but I would be ready with a new one.

Let me know how this works out for you.

Benjamin

Have it replaced.

Clean well the inside of the oven, if you keep having the problem and the inside is clean, then the magnetron is starting to go.

my guess would be the wave cover. sometimes they smoke and makes sparking sounds. does it still heat food?...if it does, then its not the magnetron.