The button is near the antenna wire on the back of the system.
Garage door remote signal weak.
On most of the newer garage door openers there is a little led light next to the learn button on the back of the opener.
Multiple garage door opener troubleshooting test start by unplugging the opener that has good range powering down this unit.
Press the learn button on your garage door motor to reset the current codes and transmitters and wait for the red indicator light to begin blinking.
It flashes because it s hearing the radio signal from your transmitter remote.
If you watch that little light while you push the button on your remote you will see it flash.
If the bad opener suddenly has good range again then the other unit in your garage is causing rf interference.
If your remote works correctly check that the opener s antennae doesn t have any excess debris buildup is pointed toward the door and isn t broken.
Stand within 20 feet of your garage door and attempt pressing the button if your remote is further away from the door the signal won t be strong enough to prompt the door.
Step 2 press the open button on your remote transmitter three times while inside of your garage and pointed at the motor.