If the main light flashes 10 times you have a door sensor problem. Make sure the small light on each sensor is lit and not blinking. If one or both of them do not light you have either a sensor problem or the wiring going to them is bad.

don, thanks for the info. The opener light flashes 10 times when the door goes back up and stops. Facing the door from inside the garage, the right sensor orange LED is lit but the left sensor green LED is not lit. However, when I walk thru the beam, the opener light turns on. I checked the sensor wire connections at the opener and all are tight. Also, wiggled the wiring going into both sensors with no effect.

I was wondering if slightly increasing the closing force on the opener might help. If one sensor LED lite is not lit, how could it still turn on the opener light when walking thru the beam?

Sometimes just a slight tweaking of the sensors will correct this situation. The sensor with the light that is off may be seeing just enough of the infrared beam to cause the light function to work but not enough to get the small light to come on and the door to operate. The light should come on when you tweak the sensor.

don,

Looks like you were right on with the diagnosis. I waved my hand in front of the sensor and realized the green LED was lit and tried the door. It closed ok! I think my first tweaking of the sensors and moving the wires worked but I didn't realize the green LED was lit due to bright sunlight. It helped to observe the LED while waving my hand in front, then I could see the LED go off and on. I hadn't tried the door since yesterday.

How would you recommend aligning the sensors? One still looks to be at an angle. Also, one is about 1/4 inch below the other. I tried putting a laser pointer on top of one and it appears it is still not aligned with the other, but did not make any more adjustments since it works now.

Thanks again.

It really isn't that critical. You can usually eyeball it and watch the lights.