KitchenAid Microwave Model KCMS1555 does not work

Assuming your inside light, turntable, and internal cooling fan all come on when you try to microwave, with the symptoms you have, I would most strongly suspect a shorted high voltage rectifier diode or a bad magnetron, or a loose and possibly corroded connection on the magnetron's terminal.

The diode is a fairly cheap fix, and the mag will cost more.

If you or someone you know decide to look into it, we have critical safety information and disassembly information at our site, and our link is at our listing here on FixYa.

There should be a "mini-manual" (tech sheet) hidden inside the unit behind the control panel or hidden on the left side behind the grille, which is very helpful when troubleshooting, testing, and locating components.

At our Web site, we have a video available showing how to remove a typical over the range control panel assembly in under 5 minutes.

If you don't find your mini-manual, or if you want to look at it before removing the controller, you can download it here.

Here are some links you or someone you know can use for test help, but read their safety warnings first:

http://www.gallawa.com/microtech/diode.html
(if it's not shorted or burned, it's probably okay)

http://www.gallawa.com/microtech/mag_test.html

http://www.gallawa.com/microtech/xformer.html

http://www.gallawa.com/microtech/cap_test.html

You can find links to helpful exploded view diagrams and part ordering help here. I recommend that you bookmark that link to your favorites.

Accessing some components for testing and possible replacement will require you to remove the oven from the wall.

If so, the installation instructions are very handy, and it's best to have two people since the microwave can be heavy and awkward.

You can download owner's manuals and installation instructions for several brands (including Amana, Jenn-Air, Kitchenaid, Litton, Maytag, Roper, Tappan, Thermador and Whirlpool) here.

If it's within the magnetron portion of the warranty (usually 5-9 years) but out of the original full warranty (usually 1 year), then your manufacturer will cover the part cost, but not the cost to visit you (usually $75 -90) or the labor charge to do the work(usually $75 -90 more) . See the model tag in or on the unit for the date of manufacture.

If nothing else, you can save about $75 by taking it to the shop yourself.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.