some cheaper microwaves can turn on by themselves due to a fault in the circuitry,a fluctuation in the mains can cause it when I worked for hoover we had all sorts of probs with the cheap ovens hoover had,so you have two choices,either turn it off at the plug top,or buy new unit ,
mm
June 2013
I can answer this question...
how can i stop my sharp r 1480 microwave from turning on for no reason all ?