On Nov 3, 7:12*pm, Oren wrote:
On Tue, 3 Nov 2009 13:38:20 -0800 (PST), DerbyDad03

wrote:
On Nov 3, 9:46*am, "pacca" wrote:
I have lift-master garage door opener , at times when I close the door it
will reverse it self when it reaches the bottom , it's a chain drive 1/2
horse opener, *any body have had this problem.Thanks

It's kind of funny how so many people assume that all GDO's are
equipped with electric eyes these days.

In this case I say the "lift-master" brand uses sensors.

I'm only familiar with one GDO maker (Mom N Pop) that makes an opener
where all the sensors are in the operator.

I say Derby's point is valid. I have a Moore-Matic unit in my
current garage that is 24 years old and has no electric eye sensor.
I also have installed Sears units from back in the early 80s that had
no electric eye sensors. I'm sure there are pleny of other ones out
there that are still in use before the saftey reqt became mandatory.