What could make random keys on a laptop keyboard suddenly fail? There has been no fluid spills, no mechanical damage, it does get heavy use. Occasionally in the past there has been a crumb or gradu making the odd key stick but that has always been easily rectified. Could it be a dirty connector? For the last week, these keys have not worked at all five six left side CTRL Delete dash I think there are others. Dell Latitude fifty three hundred, 2 yrs old.