• ** REMEMBER! **The microwave can still shock you even unplugged!!

    ALWAYS discharge the high-voltage capacitor first if you even think your hands will come close to any HIGH VOLTAGE components.

    Jeff mentions this: Anything in the high voltage ( magnetron, capacitor, diode, wires to and from ):
    ...Use a metal ( not the shiny chrome type ) screw driver with a insulated handle to short across ( touch both at the same time ) the terminals of the high voltage capacitor to discharge it.

    From Jeff's site: http://www.applianceaid.com/component-testing.php

    Jake

Panasonic NN-t99sfr

candela

Premium Member
Joined
Nov 27, 2006
Messages
13
Location
Tampa, FL
Hi again Jake,

I have an issue with a Panasonic NN-t99sfr. One would enter the heating time and press start. The microwave would run for 2 seconds and then just stop. If we select the "sensor preheat" button and press start, the microwave would run a bit longer and stop. If I repeat the last step a few times, at the point where the microwave would normally just shut off, you can see a draw in power, the microwave will change speeds and at that point would start heating. Once this occurs we can heat something for a few minutes here or there and then the microwave would start acting up all over again. I unplugged it and left it unplugged for 30 seconds. That did not work, I currently have it unplugged and plan on leaving it unplugged all night.
 

jeff1

Appliance Tech - Moderator
Staff member
Joined
Oct 10, 2004
Messages
24,008
Location
Ontario, Canada
Hi,

Model# won't come up for me, found a couple close...

NN-T993SF NN-T994SF

One would enter the heating time and press start. The microwave would run for 2 seconds and then just stop

More often than not a bad magnetron and inverter board.

jeff.
 

candela

Premium Member
Joined
Nov 27, 2006
Messages
13
Location
Tampa, FL
Yes sir, it is the NN-T994SFR. Thank you for pointing it out. Bad magnetron or inverter board? Is there a schematic or diagram to this unit available? Do you guys have it/them available?
 

missoulajim

Member
Joined
Jul 28, 2007
Messages
1
Location
Missoula
Panasonic NN-T994SFR

Jeff and Candela,

I also have a Panasonic Microwave NN-T994SFR, and it seems to be malfunctioning the same way. When I press start, it makes a soft, intermittent buzzing sound 4 or 5 times and then turns off, total on time about 20-25 seconds. Were you able to fix your unit? If so, was repair was required?

Thanks, MissoulaJim
 
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