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Question about Panasonic NN-T990SA Microwave Oven

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Microwave quit Microwave recently started "stuttering" and has now quit. After selecting power level and time + Start, the turntable turns a few degrees in each direction, the light comes on, and a few soft sizzles or pops are heard behind the button pad, then the unit stops. The clock counts down a few more seconds, then the unit goes off completely. The time returns to the clock as if nothing had happened. At first, simply restarting it would make it work. Now, the turntable doesn't even turn. The light inside comes on, the time starts counting down. After a few seconds, the sizzle sound starts for a second, and the unit stops. There is no electrical odor as if contacts are burning up. Has been a wonderful microwave. Worth fixing or should I buy a new one? Thanks

Posted by Keith Zimmerman on

  • Anonymous Mar 27, 2014

    When I push start it runs for just a few second then goes into cool down mode and nothing gets cooked

  • Anonymous Mar 27, 2014




1 Answer

William Miller

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I would suspect either door switches or an intermittent control circuit board, either of which can be repaired. Opening the door while cooking (without first hitting the STOP pad) is the primary cause of door switch failure over time. I have a text file on my site called "doorsw.txt" which helps in diagnosing and repairing door switch problems. You can find the file via a Google search. It will help you check and replace the door switches if you or an able friend is so inclined. In some cases, the problem is a bad connection or a bad relay on the control board. That's something we see fairly often, and we repair them for only $32.50 nationwide.

Posted on Oct 12, 2006


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See page 14 and 15 in the user manual.

Microwave starts then quits, turntable doen't turn

At this time we recommend you locate an authorized service center using the below link. Welcome to Panasonic Online Repair

The problem is that when I press the 'Start' button, nothing happens. The clock is working, the fan is working, but I cannot cook anything even after I have entered the time and the power level

If when you press the start button the turntable starts but no heat then magnetron is faulty otherwise if nothing happens then the touchpad itself is faulty.

My microwave want cook


and/or circuit breakers, particularly in the case of recent power failure, and reset if necessary.

Unplug the microwave, wait 30 seconds and plug back in to the power supply to reset the microcomputer.

Open and close the microwave door firmly and press "Stop/Reset." Select a new cook time and press "Start."

Ensure a proper cooking temperature and/or time is chosen, as low cooking temperatures or short cooking times may prevent the microwave from heating food appropriately. Press "Power Level" to ensure the microwave is cooking at 100 percent power.

Contact an authorized service technician if the problem is still unresolved.

Microwave won't quit running and the turntable is

try power cycling it... unplug it and wait... might be a stuck relay.

Btw, I’m available to help over the phone in case u need at


How doI change the power on my microwave?

  • Press "Time Cook" or "Micro Cook."

  • Enter cooking time.

  • Press "Power Level".

  • Select a desired power level 1-10 (default is 10).

  • Press "Start"

Microwave Turn Table

This could be a failing turntable motor, but more likely your turntable support has gotten bent. That's an easier and cheaper problem to solve. Excessive heat can sometimes make the legs of the support bend so that the center is raised up far enough that it won't always make good contact with the motor. You can test this by running the microwave empty for a few seconds. It may hesitate to turn or stutter. Next try it with a bowl with several cups of water in it. The extra weight may push it down so it makes good contact and runs without a hitch. The way I fix these is to use a stove burner or a torch to heat up the legs and bend them up a bit. Then I quickly set up or clamp the support so it's held in the proper position for a few minutes until it cools. One way to hold the heated support in position is to place an object under the end of each leg and put something slightly heavy on top of it in the middle. If you need a new motor or just want to see helpful exploded views of your model, see the GE or Sears parts Web site:
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