An older unit?
My limited experience with a 10 year old Genie opener with failed control
board: check carefully for a corroded trace. [Perhaps more expecetd here in
Hawaii but could happen anywhere as the Genie board was not well protected
from the environment.]


"Charles" wrote in message
...


"tm" wrote in message ...


"Charles" wrote in message
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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.