"peter" wrote in message
news:ktMXh.8521$oo5.8213@trndny06...

"Jack S" wrote in message
ink.net...
Some weeks ago, it started reversing before completely opening or
closing. A few tries were needed to get it to function right.

Garage door openers have safety mechanism that reverses direction when it
senses resistance.

No, the door is fine, and the malfunction occurs with the door disconnected
from the "runner".

It might be the logic board, which means the whole thing is shot.




Perhaps this is a clue that something is binding?

I made sure the door was balanced and lubed everything, to no effect.

I assume you are able to opena and close the door manually with little
effort and with no binding?

Then it quit working - the motor would run, but no door rail movement.

Try running the opener with the door disengaged and see if there is any
noticeable kinks in the movement.

Even if it passes both test, there could still be something binding when
the door and the opener are linked. Perhaps next time you see this problem
try to "help" the door by hand as it opens/closes and see if it reduces
the reversal. You may also sense a kink in the door as it opens/closes.
Unfortunately, to do this test you have to repair the broken part again.

I opened things up and found the main screw drive housing was broken and
kept the drive gears from engaging right.

Could the part be broken due to excessive opening/closing force? If so, it
reinforces the clue that something is binding.