Question about Kenmore 89980 Microwave Oven

1 Answer

It turns on, lights everything, but it doesn't heat at all. I'm assuming it is a fuse, but don't know where the fuses are since it is a built in. The model is actually a 721-8975590 but that option was not there.

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 999 Answers

This could be anything from a thermal fuse as you suggest or a door switch or a relay on the control board or the magnatron. This is a process of determining what it isn't until the problem is found. It requires some electronics knowledge and will be working around dangerous voltages. Not a project for the inexperienced or untrained. I would not recommend attempting unless the above requirements are met.

Posted on Apr 27, 2010


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Lg micro wave turns on but doesn't heat

A word of caution.......if you are familiar with microwave ovens, you know how to discharge the big capacitor in the seconday-circuit, and what can happen if you don`t! BE CAREFULL!

If your microwave oven runs normally, but won`t heat, suspect a primary-circuit fuse. Always replace with a fuse of the same voltage and amp rating. Also, check all electrical connections. Again, be sure to discharge the big capacitor so as to avoid dangerous shock.

Another common problem and simple check is the power diode. Simply check for continuity. If you get continuity in both directions with a volt-ohm meter, replace the power-diode.

If you have the proper meter, check the secondary-circuit capacitor. The capacitor can be a little pricey if it is bad.

If that doesn`t do it, the problem is likely the primary-secondary transformer. Unfortunately, the cost of the replacement part is probably more expensive than buying a new microwave oven.

Mar 03, 2015 | LG Microwave Ovens

1 Answer

GE Microwave JVM1540LM2CS Doesn't Heat

The turntable and the magnetron are two separate items and one should not impact the other. Since the other items are working it is doubtful that the fuse is bad. Also you need to know that the proper way to work on a microwave requires the use of special equipment to check for microwave leakage, it is not recommended to service them yourself.

Jan 22, 2018 | Microwave Ovens

1 Answer

Maytag microwave problem everything seemingly works but does not heat. Help

see this causes and fix it. God bless you
Diode The high voltage diode converts the A/C power output of the transformer to D/C, doubling the voltage to nearly 5,000 volts. This high voltage powers the magnetron which emits the energy that cooks the food. If the diode burns out, a lower A/C voltage reaches the magnetron, which is not sufficient to power the magnetron. When the diode fails it is often visibly burned out. If it appears to be good, it can be tested with a volt-Ohm meter capable of testing diodes. High voltage diodes frequently fail and are one of the most common points of failure in a microwave oven.

Door Switch If the microwave does not heat, one of the door switches might be defective. Microwave ovens normally have three door switches, if any of them fail the microwave does not turn on and does not heat. Check the switches for continuity with an Ohm meter.

Magnetron If the microwave oven doesn't heat the magnetron tube might have burned out. The magnetron uses high voltage, high current DC power to generate the microwave frequency that cooks the food. If the microwave oven is turned on when it is empty this can cause the magnetron to burn out. Once it is burned out it has to be replaced, it's not repairable.

High Voltage Capacitor If the microwave doesn't heat the high voltage capacitor might be defective. The high voltage capacitor works with the high voltage diode to convert the output of the transformer to DC voltage and to double the output voltage. If the capacitor is burned out the entire high voltage circuit stops working properly. The high voltage capacitor can be checked with a special VOM meter which has a capacitance testing capability. Be aware that the high voltage capacitor can retain a charge of more than 3,000 volts and can injure or kill a person if not handled properly. Only trained technicians should perform this type of testing.

High Voltage Transformer If the microwave does not heat, the high voltage transformer might be burned out. Microwave ovens produce a very high voltage in order to power the magnetron antenna, which emits the energy that cooks the food.

Thermal Fuse If the microwave doesn't heat the thermal fuse may have blown. It can be tested for continuity. Watch our fuse testing video for more information.
Thermoprotector If the microwave doesn't heat the thermoprotector may have tripped. This is a safety device to prevent the microwave from overheating. It can be tested for continuity to see if it's blown.

Main Control Board If the microwave doesn't heat the main control board may be defective. This is not common. When a microwave doesn't heat the problem is usually within the high voltage circuit; either the high voltage capacitor, diode, transformer or magnetron.


Oct 01, 2012 | Maytag MMV4205 Microwave Oven

1 Answer

Don't know if its a fuse !!! microwave just

If the oven is totally dead it may be that the line fuse is blown, but other things can cause the problem too. To figure out what's wrong you'll need the proper test equipment (at least a volt-ohmmeter) and experience with reading the circuit diagram, measuring voltages and checking parts. If you have an ohmmeter available, you can check the fuse at least, which is under the cover near where the line cord enters the cabinet. A good fuse will have a very low resistance while a bad one will have very high or infinite resistance. IF YOU DECIDE TO TRY THIS BE SURE THE OVEN IS UNPLUGGED FROM THE AC OUTLET. Sometimes the trouble is that the fuse holder doesn't grip the ends of the fuse tightly enough, and this causes heating which can damage the fuse. If the fuse seems loose in the holder, squeezing the spring clips inward to improve the grip and replacing the fuse may be all that's needed to fix the oven. If the fuse blows again it's a sign there is more wrong. If the fuse is good but the oven is dead, the trouble might be in the control circuit board.

Microwave ovens are dangerous, with hazardous voltages THAT CAN KILL YOU if you don't know what you're doing, so you may want to leave other diagnosing and repairs to a professional. If this is a basic countertop oven, you might find it cheaper just to replace it, since repair cost may be as much (or more) then the cost of a new one. For a high-end model, over the range or custom installation, repair may be worthwhile. I would suggest getting an estimate for the repair and then deciding what to do.

Jul 16, 2011 | GE Microwave Ovens

1 Answer

Need to replace fuse in Kenmore Elite microwave ove (#85210). Lights are working, but no heat generation. I assume it is the fuse.

If everything works, but the microwave oven does not heat, this is commonly caused by a failed magnetron and NOT a fuse. The magnetron is the heart of the microwave oven and it produces the RF energy that is used to heat your food. In order to replace a defective magnetron, you will need to consider the following:

1. You will need to uninstall the oven from over the range in order to replace the part (you will need to do this anyway, if you decide to buy a replacement oven).

2. Ensure the oven is UNPLUGGED before servicing anything inside the cabinet and remove the exterior case in order to access the magnetron. There are several websites that you can use that illustrate how the oven is assembled: is another site that is a great parts resource, but usually doesn't have a well defined component breakdown illustration.
NOTE: If you've never repaired an appliance on your own before, a microwave oven is usually not a recommended appliance to start with. Some models can be rather involved in taking apart.

3. The magnetron replacement cost will depend upon the model number, but generally costs around $100.
4. Some model microwave ovens have a thermal cut-out (TCO) associated with the magentron circuit, and/or oven cavity. If these small thermostats trip, they usually shut-down the entire oven. The lights would not work and the carousel would not turn. You will need to remove the thermostat from the oven (if equipped) and take a resistance check across the component terminals to determine if it is good or not. A low resistance reading indicates a good thermostat. An infinite reading, indicates a blown thermostat and needs to be replaced. The average replacement cost is about $10. I would recommend you check any fuses associated with the oven before assuming the magnetron has failed.
Review the parts illustrations at the recommended websites to identify and locate parts, and to see if this is something that you may be able easily take apart and reassemble.

If you have any questions, please post back with your complete MODEL NUMBER and let me know. I hope you find this information helpful.

CAUTION: DO NOT operate a microwave oven with the exterior cover off. The voltage inside the High Voltage network where the magnetron is installed can exceed 3,000 volts!

Apr 25, 2011 | Kenmore 80809 Microwave Oven

1 Answer

The microwave turns on but does not get hot. The light is on, the the clock, the timer and everything works, except that the food does not get hot. I tried to heat up some water and doesn not change its...

you need to remove the outer cover,then carefully discharge the high voltage capacitor with 2 insulated screwdrivers or an insulated jumper wire,then test this and the high voltage diode and the internal ceramic fuse for continuity

Nov 15, 2010 | Amana ACO1860 Microwave Oven

1 Answer

KitchenAid KCM2145JSS-1 built-in Doesn't Heat

Everything working is a real good sign. Most likely all thats wrong with your unit is a blown fuse. Go to and you will find the fuse. It's behind the touch pad with most all the other workings. Very easy to replace and cost only $11.76. It looks like an old round glass car fuse but it's made just for micro waves. It's most likely a 20 amp fuse. To get to it, take all the screws out from the back that hols the case on. once you have removed the case you will be able to locate the fuse. Good luck.

Dec 19, 2009 | KitchenAid KCMS145J Microwave Oven

1 Answer

It just stopped heating yesterday but the light

you say it has aloud hum to it? And everything works but no heat.Im going to give you a list of things it could be and you'll have to take microwave apart to do the work. Beforre you start get some small trays or pill bottles to put screws in. Make sure when you take a screw out you know where it goes back because all the screws may not be same length. First, You may have a blown fuse in the HV transformer primary circuit, The HV transformer is the largest thing you'll see when you take the cabinet of the frame.Second,bad connections for the magnetron filament the magnetron will have what looks like fins or louvers around it.look for bad wire connections. Third, could be a faulty thermal protector or fuse, More than likely its either going to be the HV transformer or the magnetron thats bad.

Sep 13, 2009 | GE XL1800 1100 Watts Microwave Oven

1 Answer

Microwave GE spacemaker does everthing but heat up.

I am assuming that when you say everything works, that tells me that your control panel comes on and when you press the start button to heat something up the light comes on inside the microwave and the table turns and that it just does not heat. There is only one fuse inside the microwave and it is rated at 15amps. I can tell you now that it is not your fuse but your magnetron that is bad. However, you can unplug everything and take the cover off and you will see the ceramic fuse. To check it you need a continuity tester like an ohmmeter. As I said though since it is the only fuse and everything comes on it is not the fuse. The magnetron needs to be replaced then it will heat up fine and the table will turn. Replacing the magnetron can be done if you are a do it yourselfer. Once you unplug the microwave and take the cover off. The magnetron sits right behind but on top of where your control panel is. It is only held in place with three or four screws and has only three to four wires that unplug at a couple of places. Be sure to note which wires go where. Find a magnetron at either a local tv repair shop since they may have a used one that works that will fit in your microwave, or go to a local electronics supply house or get on the internet and find one there. Good luck and God bless. Let me know if there is anything I can do to help you.

Jan 21, 2009 | GE Spacemaker JVM1640SJ Microwave Oven

2 Answers

Microwave turns on, but no heat or turntable movement

The problem is that the magnatron is not getting power. Chance is that if could be a bolwn fuse inside the unit. If the fuse don't fix it then that leaves the charging diode, capacitor or the magnatron, or high voltage xformer of which without technical epertize I would not recomend attempting to replace. good luck

May 14, 2008 | Hotpoint RVM1635 Microwave Oven

Not finding what you are looking for?
Microwave Ovens Logo

Related Topics:

112 people viewed this question

Ask a Question

Usually answered in minutes!

Top Kenmore Microwave Ovens Experts

William Miller
William Miller

Level 3 Expert

9098 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17130 Answers


Level 2 Expert

228 Answers

Are you a Kenmore Microwave Oven Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides