I have a Sears screw drive opener, model #953992, 1/2 hp. I had this
opener running for quite a while, and then had a bad water leak
upstairs...water leaked into the garage ceiling and damaged the
opener. I fixed all the water damage and went down and bought the
exact same opener, thinking all I had to do was change the motor, and
I wouldn't have to deal with assembling a new rail, door sensors etc.
I put the new motor on as planned and fired it up. All it did was hum
briefly and stop, and then gave me 5 blinking lights in the back. I
didn't pay any attention to where the trolley was on the rail when I
installed it, but (after reading the directions) I learned that it was
supposed to be positioned about 9" from the end of the rail, nearest
the door. So I moved the trolley, but in the meantime, I turned the
heck out of the adjustment screws trying to figure out what was wrong.
So now, the door runs okay, but runs the door all the way down, and
right back up til the trolley hits the limit pin near the motor and
stops. I try adjusting the limit screws, but it doesn't seem like
it's doing anything. My fear is that I messed with them so much that
they backed all the way out, or no longer work for some reason.
I'm thinking of calling a pro at this point, but if I could get it
back to some kind of reference point to start out, I think I could get
it adjusted...right now I have no idea where I'm at.
Any suggestions or should I call a pro?