Why does the fan keep running on a kenmore spacemaster 300?

William Miller

• 9179 Answers
• Posted on Jun 08, 2008

SOURCE: Just stop working

A microwave can be dead for many reasons.

If the fuse is good, it may be an open thermostat or thermal cutout (TCO) / thermal fuse on or near the magnetron or on top of the cavity / body of the oven.

If it goes dead for a while during or after cooking then comes back on, the magnetron is probably overheating and causing the magnetron thermostat to open.

Then when it cools, it closes the circuit and allows power through again.

When checking thermostats, if it has a hood fan thermostat, that should read open, as opposed to the others, which should read closed.

If it went dead almost immediately after pressing the Start pad, that's usually a shorted high-voltage capacitor.

If it went dead a few seconds after pressing the Start pad, that's usually a failing high-voltage transformer.

If it goes dead or blows the breaker when you plug it in or open or close the door, then there's a problem with a door switch or door switch mount.

If it's intermittent or random, it may be a bad connection, usually on the control board or a loose fuse holder, or even an intermittent fuse.

You should do a continuity test on the fuse while it's in the holder (with the microwave unplugged, of course) then turn the fuse by hand or take it out and put it back in, then test it again.

If you remove the fuse, then press the meter leads against the ends, it can allow internal contact to be made and make a bad fuse appear to be good.

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: http://tinyurl.com/yzjozk

You can probably find an exploded view by entering your FULL model number here: http://www.searspartsdirect.com

We're happy to help and we appreciate your thoughtful rating of our answer.

SOURCE: Kenmore spacemaster microwave Auto recipe 300

My 300 model number is 564 8898410.

Must be a later model.

I'm looking online for a operating manual.

William Miller

• 9179 Answers
• Posted on Jan 10, 2010

SOURCE: kenmore spacemaster will turn on, display appears

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.

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 handy exploded views at the Sears Parts Site.

BUT once you have the part number from the Sears site, you can often get the parts cheaper here.

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

SOURCE: Emerson Microwave Oven Model MWG9115SL: At

I suggest you check and/or replace the door interlock switches.
Hopr this helps.

SOURCE: Kenmore spacemaster microwave Auto recipe

Dead appliance, power on wall outlet.

YOUR SAFETY IS PARAMOUNT!

Attempt this only if you are competent.

If your appliance has absolutely no functions at all, remove it from the mains supply, remove the case and see where the mains lead goes in to the appliance and follow the cable until you find the main fuse.
ONLY USE THE SAME TYPE AND RATING OF FUSE TO REPLACE IT.
The usual cause of this fuse failure is the door switches are contaminated or sticking. Check the door switches before putting power back on to the appliance.
Hope this helps.