CMD89

Just wondering if ony others have experienced this problem. I already know how to operate the keypad, its just that the damn thing does not respond when you push any of the buttons. It will work for an month or two and then not work for 10 months or so. Its just as if the thing was dead and then it comes back to life all of a sudden. I don't think its related to the temperature or anything. Any help would be much appreciated.

Chris