On Sep 19, 1:11 pm, wrote:
I've tried so many things to correct my problem with my garage door
opener. I have an Access Master chain driven 1/2 hp. opener. Here
are the symptoms:

The opener will only move about 6 inches then stop on the way down.
Sometimes it will go all the way up, other times only a few feet. The
distance of travel up or down is intermittent. Generally though on
the way down it will not go all the way down in one click of the
button. I have to click it about 7-10 times to get it to go all the
way down.

Things I've tried:

Cleaning the light sensors
Realigning the light sensors (although I didn't have the proper tools)
Adjusting the force adjustments
Adjusting the distance limits
Pulling the emergency latch and testing without the garage door load
Reseting the opener
Unplugging the opener
Testing from the wall switch
Testing from the vehicle switches

Is there an easy way to check on sensor alignment? I thought about
using dry ice, but I'm not sure if the light would show up or not in
the "fog"

I'm guessing that i have something failed in my electronics portion of
the opener. I have not pulled that out to look at it, and it's mostly
surface mount technology so I'm not sure if I could even tell by
looking at it anyway.

Thanks,
Michael

Typically, if the sensors are not aligned correctly, the door won't
operate at all. Since you get some movement, they are probably
working. But to be sure, you can move the transmitter and receiver
right next to each other or completely bypass them if you know how to
wire it that way.