Display shows a green key, but microwave function not working. What to do?

IT MEANS THAT ITS TOO HOT AND PULL THE BUTTEN OFF

same thing as Samsung - shorted key - google manual

In this case as the display does not show a clock then it seems the program controller is not working correctly. So check power - step down supply, if the pads are responding- if not faulty pads. Also the door switches, if the switch contact are not good then it will not trigger the processor to switch on the waveguides. If the lights or fan work without any display or action of program being triggered to start then it can be a possible fault on the main board or the processor. Sometimes insect secretion can short the board and display panel and so the processor can work in such an erratic manner. If so clean,solder and reset the board.

Now identify the parts by clicking this link: http://www.espares.co.uk/advice/microwave/a/5/141/identifying-microwave-parts.html

Now unless the display works and the processor starts to switch on the MAGNETRON , the table and light will also switch on as it must heat.

So it is necessary to check the main controller unit as it seems to be the suspect..

I would say you require a new control panel. Consult an authorised Panasonic service centre for repair.

Here you go.

The Child Lock shuts down the control panel pads to prevent
unintended use of the microwave oven.
When the control is locked, only the Vent Fan and Light pads will
function.
To Lock/Unlock Control: The microwave oven and Timer must
be off. Touch and hold START for 5 seconds until 2 tones sound
and a lock icon appears on the display. Repeat to unlock and
remove the lock icon from display.

HI. this is a code that represents a failed key pad or touch pad membrane board. replacing this failed touch pad will fix this issue. This touch pad board is separate from the actual control board.

The contacts on the electronic board inside the oven for the display need to be cleaned. You should be able to get into the microwave from the back and unscrew the board. One side of the board will have a row of contacts that can be cleaned using first rubbing with an ink eraser and then with a q tip dipped in isopropanol (rubbing alcohol).
I lost all contact with the display on my microwave and this really helped get the key functions back.

Neil

i had same problen, i changed the fuse inside the microwave, works good now