Phone was working fine all day but now my keyboard is not working at all! Did not drop it, wet it, sit on it....Is there anyway to fix this?

have you done a battery pull?

Yep...

I dont want to imply, but most of the time, this sort of thing is caused by either moisture or droppage. Both of which, you said did not occur that you know of. Is it possible this a used device or someone else may have harmed it?