Since a few days ago our garage door opener will only function if we
pull right up to the door and press the button. Previously, with each
of our 2 remotes, we could press the button out at the end of the
driveway (75') and it would work.

I suspected week batteries and replaced them in each of the remotes
but still we have to be right up next to the door before it will get
the signal and open. The antenna appears to be ok on the opener.

Any ideas what could have caused this sudden problem?

The door opener is a Craftsman 1/2 HP circa 2002 or 2003.

Thanks in advance,
Mike