Photo Sensor that has been spider webbed with debris. This type of blockage is a serious issue when you need to not have your door to not misbehave. This is a sensor that will need to be cleaned.

Photo sensor that has blockage. We are able to correct this issue with out spending lots of extra time doing this kind of diagnostic. The sensors can be cleaned manually

Photoeye sensors that have been cleaned and the signal strengthened. Debris and material needs to be taken away form the photo eyes for the sensors to properly work. This maintence is essential for your door to work properly.