Stanley Professional 7100 Manual
The knobs that you 'messed' with is most likely the UP and DOWN limits. If it opens like it should! Then ignore the 'up' knob but, the down knob is the one your gonna want to turn to the - side of its opinion and not the + side whitch is already turned up too much, whitch is why as it is closing it retrieves back as it opens becouse the operator is sending the door too fare down. So by dacking off the down limit knob a little at a time and trying to close it till it stops ounce it gets to the full close position. The knobs should have indicators of arrows one with a arrow up and the other with one pointing down. Posted on Oct 16, 2016. 91 Answers SOURCE: That normally happens when the sensors aren't aligned.
Stanley St500 Manual
Both sensors have led lights on them the yellow/orange one will stay on all the time the green one will go out if it cant see the other sensor. Possibly theres a wire that's broken or the other sensor is really out of alignment. Check every inch of wiring from the sensor to the opener, remove wire nuts if present and check the connections. The wires that are used are small, solid and can break easily.
Stanley Garage Door Manuals
Also see if there's a staple that's too tight, move the wire abit where it's stapled and look for damage. Posted on Jun 27, 2008.