"tm" wrote in message ...


"Charles" wrote in message
...
No joy on finding a schematic for a LiftMaster control board. Thought I'd
ask here.

The remotes (4 of them) work flawlessly to open the door. They also work
to close the door, but only after the built-in overhead light turns off.
That takes about 2 minutes.

Checked the obvious for the beam sensor: sensor obstruction, sensor
wiring, sensor lenses, sensor alignment. The wall switch always works.

Any ideas?

Thanks!

Are you using CFLs in the unit?

No, just an ordinary incandescent. I see your point ... high frequency
interference.