If you've reset it by unplugging it for a few minutes, the next step would be to see if any moisture has been deposited on it.
This is best accomplished by removing the cover and looking at the circuit board to see if there are any rough and dull white, gray or green deposits.
(There will be a normal green coating on the board, but it is shiny and smooth).
If so, they may be cleaned off with a soft brush (like a tooth brush) or a Q-tip lightly dampened with high grade alcohol, such as 70% or better isopropyl.We have an incomplete service manual for it here
. It will be helpful, but again, it is not complete.
Also see: http://www.microwavedisplay.com/safety.txt
One can also unplug the keypad strip (see photo below) and use a soft eraser to gently scrub both sides of the end of the strip and any spots on the boar. Then plug it back in and try it again.
If it still does not work, then the keypad has failed. Sadly, they are no longer available, so the oven would have to be retired. They were great performers...We're
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