If it is a soft button like the number keys or a television remote the button has a contact material (conductive paint) on the back of the button which is part of all the numbers and other buttons on a rubber sheet. The contact material gets worn off and won't work but you can get a repair kit which requires you to take the phone apart and get to the button sheet. The kit is on Replacementremotes.com for $17. It works.
CAM, February 2009
