I think that my home had a power surge or was hit by lightning. A fan on the microwave will not shut off. The vent door opens when the microwave is in use and closes once the time is done. The fan keeps running. I need to unplug it between uses. I think that a fuse might need replacing but I cannot get to them. I was able to remove the vent door but cannot get the grill behind the door open. Is there a trick to this? I cannot find any screws and cannot get the door to slide in any direction or to pull out. Any help would be great.