Hi Sir,
First of all I am very grateful for all the timely help have always received from you.

Now I am having problem with my microwave. Sometimes, when I try to heat some vegetable(cooked) or lentils(cooked) it sparks and makes some roaring noise.
After sometime, like after a few hours or something, it starts working perfectly normal.
I don't understand what is going on. Is there a loose connection or something?
It is hardly two years old, Sharp 1500 Watt Big Microwave.
Can You please help?
Anuradhamani

Are the foods in a microwave safe container? Is there any metal at all anywhere? Even a flower decoration on the container may spark if there is metal in the paint. One of my bowls has a chrome rim so I cannot use that in the microwave. Did you leave a spoon or other utensil in the container while the food was cooking?

Also, sometimes certain foods will create sparks. Dense vegetables such as green beans, carrots, and green peppers have a higher amount of minerals in them than other food items. These minerals include iron, magnesium and selenium. The minerals act like tiny pieces of metal and create arcing effects in a microwave. The sparks result as the microwaves reflect or bounce off the metal. The arcing does not harm the food but it does prevent it from heating thoroughly.

Having read the last post, I agree that this can happen, and you do have a very powerful microwave oven. 1500W, that's a monster. The container is the most likely culprit. I would call Sharp personally to make sure they're not recalling. Microwaves have come along a long way recently but Monsters like yours which could probably make toast still shouldn't be arcing from beans. Check your containers. And be more concearned about the roaring.