Sears 1/2 HP garage door opener remote problem
Hello. I have a Sears 1/2 HP garage door opener (model 139.53615sr)that was installed when I moved in. The keypad and the hard wired remote work fine. I didn't have a remote for the car, so I purchased a 81LM remote which says it's compatible. I found the manual online and proceeded to try to add the remote. I hit the green learn button on the back of the opener and a red learning light came on. I pressed the button on the remote and held it, but nothing happened. I tried holding the learn button to reset all codes, and the red light came on and stayed on for about 30 seconds before going off. I also tried changing the battery in the new remote, just in case. Any other suggestions?