KitchenAid microwaves have advanced display screens which show things such as the time of day, cooking time, preheating timers and power level. If the display malfunctions it can be manually reset in a matter of moments using the buttons on the microwave.
Check the display of microwave. If the display reads "PF id = 27", "PF id = 30" or "Err", this indicates that there is an error and that the display must be reset.
Clear the display screen. Do this by pushing the "Lower Oven Cancel", "Upper Oven Cancel", or "Cancel Off" button (which button appears on your microwave depends on the model).
Push the "Clock Set" button and then the "Start" button to activate the clock resetting function. Use the number pad to punch in the time and then press "Clock Set" and "Start" once again. The microwave's display should now function properly.