[Rickie]

We used the timer as an alarm while making a cake in the oven, we thought. Actually the cooking timer was selected with nothing in the microwave, and was noticed after 15 minutes. The microwave was very warm, hot to the touch. I let it cool and unpluged the unit.
Now the unit only makes lukewarm water, defrost is veryyyy slow.

[PS Staff - Sheila]

You may have damage the magnetron.

Here is a link to your microwave model JVM1870BF.

For a more detailed breakdown of your microwave you will need the last part of your model number.