Can direct sunlight interrupt the sensor, preventing the door from going all the way down? At night, early mornings or on overcast days my garage door goes up and down with no problem. However, when the sun is out the door will go down partially then back up. What can cause this?
My Genie suffered the same issue, sunlight "blinding" the system.
After reading all the "fixes", it occurred to me that the one simple remedy would be to simply reverse the devices, putting the receiver pointing away from the sunlight instead of into it.
The opener doesn't care which way it's laid out; it's totally arbitrary, at the whim of the installer.
The wiring on the Genie is very simple, with two leads to each device. This can be done in either of two ways: "home runs", (a pair of leads to each device), or a "loop", (one lead going to one device, then looping over to the other one). Both circuits are electronically the same. The red wire connects to the white with black stripe and the white wire connects to the white-only wire.
It took ten minutes to do, and I didn't have to build any boxes or use any toilet paper tubes. Hope this helps.
Your garage door opener is most likely radio-based. But the transmitters are very low power. It is quite possible for atmospherics to affect radio waves.
Sometimes you can build a metal box around the receiver which will make it receive signals from predictable directions.