Chamberlain Powerdrive PD422D 1/2 HP Security Plus Screw Drive Garage Door Opener "turn light whisper door" Questions

...TURN ON THE LIGHT WHEN THE SAFETY EYE BEAM IS BROKEN. YOU COULD HAVE AN INTEMITANT OPEN CIRCUIT OR SHORT (USSUALLY UNDER A STAPLE) CAUSING THE LIGHT TO AVTIVATE FOR ABOUT 4.5 MIN. I HAVE ALSO SEEN ...

...light will not turn on. I've manually tried turning the light on and can hear a click when I press the light button. I've changed both light bulbs with new ones. I was looking for a reset button, but ...