My son held the Stop/Cancel button for 3 sec. which is suppose to put the microwave into child safety lock mode.When he did this everything cut out even the time display. Holding the button again is suppose to release this mode but this didn't work. I kept it unplugged overnight hoping the capacitors would drain down and release this function but nothing. So my question is, how do you reset the unit? The microwave is less than a year old.