How do I replace a fuse on a Kenmore over the oven microwave oven. Model number 72189941490? Everything works but once I set time,etc., to cook or reheat, the time shows going down to zero, but no hea

I had a similar problem once with an older Kenmore microwave, which at the time, were actually made by LG. After removing the cabinet, there was a small automotive type fuse in a clip-in fuse holder which proved to be "open" after checking it for continuity with a test meter. I replaced the fuse with the EXACT type and rating, and continued to use the oven for several more years until I gave it away. Please note, that microwave ovens are not something that you want to mess around with. Make absolutely certain that you have unplugged it before doing anything. In my case, I suspect the after several years of trouble-free use, the fuse had failed, -likely due to age. In your case, it may be a similar issue, so you might want to see if your microwave oven has a similar replaceable fuse. Beyond that, I would strongly suggest taking it to an approved service facility. Also, NEVER operate the microwave until you have replaced all covers, cabinet, etc. to it's original state.

Planned obsolescence.

Check those 3 micro switches in the door latch assembly. A bad microswitch can blow the main fuse. This usually ruins the microswitch.

Considering the problems you are having it would be cheaper to replace the microwave oven.

The magnetron is shorted or the inverter board is defective if microwave is 7 years old or less.

There is an inline fuse that is accessed by removing the outer casing. Follow the power line in to the magnatron and you should see the fuse. Make sure the fuse that you replace it with is the same as the one you removed. If this doesnt work then the magnatron has gone out.

Dave

Sounds like the magnatron tube or it's fuse.

The turntable system consists of the motor, the coupler, the turntable support with rollers, and the tray.

You can see and hear a video of how a turntable motor should sound when you rotate it by hand.

If yours sounds like it's grinding, etc., you may have a bad motor or plastic coupler.

To replace either, you need to unplug power, then remove the bottom cover of the oven.

You can usually find exploded views and order parts by entering your model number here at the Sears parts site.

A full Sears/Kenmore model number has 3 digits, a dot, then 8 more digits, such as ###.########

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

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.

The 665 prefix on your model number is Whirlpool, but I haven't found the code "d" listed yet.

Can you set the cooking time?

If so, what happens when you press Start?

I'll post back if I find the codes or if you have other info and I can help further.