I have double doors to my garage operated by two craftsman door openers. One Opener is about 20 yrs old, the other only 2 years old. Suddenly, in the last week or so, both doors quit functioning with the remotes and keypad entry. The remotes only work at very close range (like standing directly beneath the opener). Replacing the batteries had no effect. My neighbor has had similar experiences with a different brand opener. What can be the cause and how can I fix it?