As garage door experts customers rely on us to help them solve small and large problems. We take great pride in knowing that we can solve most if not all garage door problems. We received a call from a customer stating that the sun was interfering with his safety sensors. This customer has a liftmaster 3240 screw drive opener. He had tried cleaning the safety sensors to see if that would solve the problem of the garage door not closing completely and was unsuccessful. When the sunlight interferes with the safety sensors there are two steps to correcting the issue. The first step is to keep the safety sensor with the green LED on the opposite side of where the sun is hitting. This typically fixes the issue. The second step is to replace the safety sensors and keep the green LED safety sensor on the side opposite to where the sun is hitting. Many times safety sensors have dirt inside them or moisture that can add to the issue of the sunlight interfering with the signal. The safety sensors are located on the bottom right and left hand corners of the garage door. This location makes them prone to having dirt and moisture in them. New safety sensors have an approximate cost of 30-45 US dollars. Replacing the safety sensors does not require any special tools. We always suggest contacting technical support specific to your garage door opener manufacturer. In this case we provide the link for Liftmaster tech support as we a referring to one of their product.