RE: Overhead garage door opener Model 990 (screw drive)

I have a garage door opener that when activated, always stops in a certain spot and won't open up any higher.

What do you think is the problem?

 

Probably a maladjusted limit switch.

 

Without knowing anymore it's hard to say. Is it stopping there because it was set to do so (limit switch location)? Or, is it stopping there because of something wrong like a protruding bolt blocking the track or the door is binding? I have also seen stock size openers installed on taller doors. The door only opens partially because that's all the track the opener has.

 

Disengage the door from the garage door track. See if the door moves its full limit up and down while not attached to the opener. If it moves freely try as mantioned to look for a limit switch, sometimes they are located on top of the garage door opener's rail. Also try cycling the garage door backwards and forwards without the door attached. If chain driven, it may reset the chain to the start position. In otherwords, your door might me attached at the center of the chain, moves to its limit and stops, but the door is only half way open.

 

Screw drives are terrible and I replace those more then any other type of opener. Check to see that the rail is still straight. A bent rail can cause binding and the trolly to stop when going up. The teeth on the trolly could be damaged, You can detach the rail from the wall above the door and slide the trolly off, flip the lever to "engage" the trolly and inspect the teeth. You will be able to tell pretty easily if they are broken or ground down. Lastly, if you have a rail that contains like 4 pieces joined together by brackets and bolts then you can check the screw drive sections. There are two retainer clips that join them together and I have seen one of them get damaged before and the trolly will get stuck on that. Check all that out and let me know how it goes.

 

This is my first Post, Can't quite find the "Black Dot" to push. My door, when activated at the wall mounted activator goes up or down about 2 feet and reverses direction. Also, the light on the operator does not work and it is not the bulb itself. Any ideas of what is wrong and how to fix?

 

When you say it goes a few feet and reverses is this only when you try to close it? Or does this happen when you try to put it up too? If it is only when you try to close it then it could be the RPM sensor or the sensor eyes. If it is the sensor eyes then you will hear the opener make a double click sound once it is fully open and you should hear the clicking ten times. If it is the rpm sensor then it will go down 2 feet and reverse and go back up with no clicking sounds. As far as the light goes I have seen openers where if you screw in the bulb extra tight it sometimes will come back on. Other times the light socket mechinism just goes out and you can order a new one online and plug it into the circuit board. I hope all this helps.

 

remeizo,
mine is a chamberlain model 350, 20+ yrs. old, the trolley also moves on a central rail, pulled by a bicycle-type chain, is this a chain drive v a worm drive? my trolley seems to be binding as the gear motor only pushes or pulls it for less than an inch [slack movement]. can i check for a bent central trolley rail in the same way as you rec. for the OP?