I have a old chamberlain garage door opener with sensors. Its motherboard started going bad - not allowing opens and closes based on transmitter. Sensors worked fine.
Replaced it with chamberlain d2101. Pretty easy install, got them swapped, chains redone, and then did the electric which was pretty easy too. Red switch first slow, white switch second slot, white sensors third spot, black/white sensors last spot.
Think we are good to go. Gives me four clicks and error code 1 arrow up 1 arrow down... Sensor issue. I check out my sensors and they are working fine and shutting down when something in the way.
I then rig the sensors that came with the unit to point to each other and see they are working... Now I get 1 arrow up and 4 arrows down, which is another kind of sensor error code.
Any other info needed?