Kitchenaid KCMS185JSS2 This inbuilt unit installed in 2003 does not heat anymore. Also it does make a bigger noise than the usual. The display is fine & it seems to run normally. Please adviise. Thanks, Hede.

Most likely causes - shorted high voltage rectifier, or failed high voltage transformer, or shorted high voltage capacitor, or shorted magnetron. If an odor accompanied the failure, high voltage rectifier or transformer most likely. All of these components operate on 4000 v, or more - with enough current to kill you. Make sure the unit is unplugged, and the high voltage capacitor is fully discharged before testing.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/david_29ad5d1dd86564b0

The magnetron has failed or the high voltage transformer is the problem, either way! it is very expensive to replace, cheaper to buy new.

i would try and see if the fuse is blown in unit ... normally behind control panel there is a in line 20 amp fuse that may have blown.... if the unit makes noises when you touch the buttons but no display then you have a bad control board assembly

If it is making a loud noise, check the diode and magnetron for damage.
BEWARE OF LETHAL VOLTAGES!
The fault may be just the diode and a reasonable cost will be involved. If it is the magnetron, depending upon where you purchase one from will command the price.
Hope that helps.

It may be a failing turntable motor, failing stirrer motor or stirrer rubbing against the stirrer cover in the ceiling of the oven. If it is arcing, that's usually grease buildup or a jammed stirrer.

We have a sound clip of what a microwave should sound like when the cooling fan and high voltage section are operating here.

A loud buzz, hum, or groan is usually a shorted high voltage rectifier diode, but a sound like gurgling into an empty coffee mug is one symptom of a failed magnetron, and yet the mag can be bad without that sound. If either of these problems exists, it will not heat.

Here are some links you or someone you know can use (in order given) for high voltage section test help, but read the safety warnings first:

http://www.gallawa.com/microtech/diode.html
(if it is NOT shorted or burned looking, it's probably fine)

http://www.gallawa.com/microtech/mag_test.html
(continuity can be good even though mag is bad!)

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

You can find links to helpful exploded view diagrams and part ordering help here.

I'd recommend that your bookmark this link to your favorites.


Accessing some parts may require you to pull the oven from the wall and remove the cover.

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.

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

I'm guessing you might mean model KCMS185JSS0, KCMS185JSS1, KCMS185JSS2, KCMS185JSS3, or KCMS185JSS5?

To allow us to help you effectively (at no charge), please post a NEW problem to FixYa, and please include your brand name and the full model number from the tag in or on the unit, your symptoms ("won't heat"), as well as the answers to these questions:

- When you try to microwave are the inside light, internal cooling fan and turntable all working?

- Is there any unusual noise or is it louder or quieter than normal?

We have a sound clip here of what a microwave should sound like when the cooling fan and high voltage section are working.

(A loud buzz, hum, or groan is usually a shorted high voltage rectifier diode, but a sound like gurgling into an empty coffee mug is one symptom of a failed magnetron, and yet the mag can be bad without that sound.)

- If yours is making an odd noise, which does it sound like?

BUT If you or someone you know wants to go ahead check out the diode and magnetron, see these links:

http://www.gallawa.com/microtech/diode.html
(if it is NOT shorted or burned looking, it's probably fine)

http://www.gallawa.com/microtech/mag_test.html
(continuity can be good even though mag is bad!)

You can find links to helpful exploded view diagrams and part ordering help here.

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

Is there any fault code displayed on the display, such as F6?

I would first suggest checking the door switches and mounts.

If they are good, I would suspect the control board. We regularly repair such control units for customers nationwide by mail for $39.95 postpaid in about a week or so with a one-year guarantee.

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 yours, or if you want to look at it without disassembling the oven, you can download it here.

Feel free to contact me directly (and please remind me of your full model number from the tag on the unit) for more information & help.

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

William E. Miller, AS-EET
[email protected]
http://www.microwavedisplay.com

If your magnetron was shorted, the unit would not heat at all.

The sound of a shorted magnetron is usually a loud hum-- but no or very little smell and no smoke.

Components in the High Voltage section -capacitor, diode- give problems if they short out.

First we should determine if it's actually cooking when you just close the door, or if it's only the light and fan running.

You can test it by putting in a cup of water and closing the door for 30-60 seconds, then checking to see if the water is warmer.

If it is actually cooking, then it's your control panel that needs to be repaired.

We regularly repair these control units for customers nationwide by mail for $39.95 postpaid in about a week with a one-year guarantee.

If it is not cooking, then you have a problem with the lower door switch (primary interlock switch) or its mount.

That's a pretty easy DIY fix. 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.

Then you can see this file: http://www.microwavedisplay.com/doorsw.txt

There should also 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.

You can usually find helpful exploded view diagrams and order parts by entering your full model number here.

Feel free to contact me directly (and please remind me of your full model number) for more information & help.

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

William E. Miller
[email protected]
http://www.microwavedisplay.com

I would recommend changing the diodes as well. This will usually take care of the problem.