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

Question edited for clarity. Question moved from Televisions https://www.google.com/search?q=Panasonic+NN9853+control+panel+schematic https://www.google.com/search?q=panasonic+nn+9853+service+manual+pdf https://www.fixya.com/support/r29874712-repairing_microwave_ovens ..

You have to take off the case. Need a T20 Tamper Torx bit and a Phillips #2 Bit. There are 2 tamper-torx screws on the case to discourage inquisitive types / prevent untrained hands from entering. Once the screws are out (5 in total), slide the cover off the back. On the right-hand side, you will see the electrics. The bulb is behind the black oval shaped fitting that lies just behind the 2 big red wires that carry the high voltage to the microwave tube. Just pry over the bend-down metal tab, and lift off the black oval, bulb is attached to it. Replace, re-install, and test with case off and door open to ensure your replacement works. Re-install the slip-off case and screws. You're done.
Kermit

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

Doug

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.

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...

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

open top cover and replace lamp

MAY BE DOOR SWITCHES

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.

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.