There are several reasons that your remote can stop working the garage door opener. When this happens, the first thing you should do is to check the batteries. Replace with a new set. Make sure you clean the connectors first in case there is corrosion.
Take a cloth and clean the eye on the IR unit. This is what allows the signal to get to the remote. Also, clean the remote eye to remove any dirt or smudging.
If both of these options fail, reset the system. In order to do that, remove the batteries from the remote and unplug the opener. Make sure both lose power for at least 30 seconds. Once you put the batteries back in and plug in the opener, try the remote again. You may need to re-program the remote in order to get it to work.
