20 Most Recent Panasonic NN-T990SA Microwave Oven Questions & Answers

Not sure of the TT series models but for the NN series models the procedure is as follows:-

If "Child" is displayed in the display window, then the child safety lock is on.

To remove the child safey lock, press the "Stop/Reset" button 3 times in fairly short succession (less than 3 seconds). The time of day or just the Colon sign (:) is then displayed

If you later want to apply the Child safety lock, then, when the time of day (or colon sign) is displayed, press "Start" 3 times (again in short succession).

Hope this helps


Panasonic... | Answered on Feb 06, 2018

The problem is an engineering defect. The mechanism that engages the door latch is mounted to a steel plate that is "L" shaped and when you close the door it pushes against and bends this plate out of position. After a while the metal plate fatigues and stays bend out of position and the door stops engaging and locking so the two safety switches inside don't get depressed. Result door won't lock and light stays on. I had to re-engineer it by cutting the tube of a pen to size and placing it in as a support bracket to put pressure on the plate so it won't bend anymore. My wife was going to throw it in the trash. Note of caution: I did cut my hand in several places trying to get the bottom cover on and off the microwave as the metal edges are razor sharp!!! I love this microwave it is my second one.

Panasonic... | Answered on Mar 10, 2015

There are a number of possible causes.

The following link will take you to a page with the diagnostic flow chart that you can use to troubleshoot this issue:
Microwave Fault Codes

This customers review of that issue may also be of some help:
Customer Reviews Panasonic NN T945SF 2 2 Cubic Foot 1250 Watt Microwave...

Panasonic... | Answered on Jan 11, 2015

you have to remove the plug and then the outer casewhich is 4-5 screws on the back,you will find a air duct on the left hand side of the magnetron which is a metal box with two wires on the bottom.the bulb hosing is kept in with a screw and a metal tab,undo the screw and remove the two wires and that is the unit you have to replace,it is called a cap less bulb as it is one unit,reassembly is the reverse.hope this helps regards les

Panasonic... | Answered on Nov 09, 2014

Plug a lamp into the wall receptical, if it works! the main fuse in the microwave has blown. Unplug, and remove the top "several screws" check under the keypad and follow wires to the circuit board, look for a silver rectangular capacitor, take a screw driver and short the two points to remove any residual voltage. Now look for a small fuse "clipped" pop with screwdriver and replace with the same current rating, assemble unit because lethal voltages are present when powered on.

Panasonic... | Answered on Oct 15, 2013

could it be that i didn't follow the manuel because i got it second hand or is it because something is wrong with it,and i have to get it fixed.

Panasonic... | Answered on Mar 20, 2013

Since no model number was posted, I have to give a general answer.

Since it was posted under Panasonic, I'll assume it's a Panasonic.

See if one of these describes what's happening:
  • Put in time, push start and unit runs for 2 seconds, relay clicks, unit goes off. Cook time on display goes off and clock time comes back. Bad upper interlock switch and charred connector
If so, see http://031d26d.namesecurehost.com/mwd/safety.txt

Otherwise, if the digital programmer circuit / controller does not get a feedback signal from the inverter for a period of 3 seconds, the controller will stop the cook cycle.

It may be a loose connection in the wiring between the inverter, magnetron, and/or control board, or maybe one of those components has failed.

If it stops after 7 seconds, it has a problem with the inverter.

Due to the lethal voltages used and produced in inverters, I do not recommend that an inexperienced person work on these.

Panasonic... | Answered on Oct 06, 2011

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