Was warming up food and it started sparking and smelled like burrned wire

From the description you have provided, the magnetron has shorted. This a job for a professional because there is lethal voltages present that will kill.

The loud noise and no heat means that the magnetron has failed. It the part that generates the microwaves that heat the food. When it fails it shorts out, causing the transformer to heat up. That is what was causing the burning smell. The cost of a replacement magnetron is around $130-150 range so it may not make sense to have it fixed.

check to be sure there is no metal objects bc this causes microwaves to reflect back to the magnetron causes sparks and burning smells in the microwave nd check that all food that may have spilled is cleaned up

IF YOU SMELLED BURNING TAHTS BAD, IT SOUNDS LIKE YOUR MAG TUBE WENT OUT (ITS WHAT MAKES THE MICROWAVES) iT WILL BE CHEAPER TO REPLACE IT, NEW UNIT STARTING FROM $115 FOR THE SAME MODEL

from what you are discribing , I would be looking at the high voltage transformer

The unit had a meltdown. Anytime you smell something thats not normal its alway an internal failure. You could send it out to be looked at but at the price to replace it your better of getting a new one.

Is this oven still under warranty? If so, take advantage. If not, remove the power plug and the case. Short out, with a screwdriver, the large can-shaped capacitor with two terminals sticking out. Check the wiring and circuit board for signs of burning. If everything looks ok, remove the thin sheet metal wave guide that sits above or beside the microwave energy port into the cooking cavity. Under the sheet metal, there is a metal fan-like device called a 'stirrer' that has a plastic bearing. Remove this stirrer and smell the bearing. If it smells like the burning wire smell, replace the stirrer. You can buy it through 'Sears Parts' online.

Absolutely not worth fixing as a brand new one with lots of features can now be purchased for as little as fifty dollars.

Unless specifically stated in the manual, you shouldn't use the microwave for warming plates. That is not it's intended use.

I suspect the microwave circuit has failed in some manner.

Reply the specific Sears model number (in the form xxx.yyyyyyyy), and I can help further.

First try cleaning the burned mark off. Dip a scrubber in lemon juice and sprinkle salt on it; this is also great for burned coffee pots. The smell can be gotten rid of this way: Boil lemon peel in water, then put the water in a spray bottle. Not only will it make your microwave smell fresh but the lemon oil will make it easier to clean. If it still smells of burning rubber, take the back off and inspect the wiring. IF you see burned wiring, please do yourself a favor and replace the microwave!

Microwaves work by making the molecules in food get "excited"-they move more-meaning, if there IS rubber burning, then there will be minute molecules of rubber in your food, which is BAD for your immune system. If it's just burned chocolate, though, it is harmless unless you are allergic.