Chain removed or on - eyes aligned and both eye lights on - button starts cyclemotor runs short while and then reverese - no limits have been reached - even removed the ''middle limit arm'' and still reverese on its own - raised and lowered the force pots as well for both up and down directions! What is it?

External power the eye

One of your sensors is moving and you need to find out why and correct it. The light flickers when the sensor is on the edge of the beam sent by the other sensor. Think of it as a flashlight.

If it is doing this in the down direction it sounds like you have a bad RPM sensor. This is a small circuit board just in front of the motor. It's function is to reverse the door when it contacts an obstacle on the way down. When the board goes bad it acts like this.

When you can close the door by holding down the wall button it IS the safety eyes or wiring.

If the eyes are mounted to the track. Many times the track wll move as the door closes causing the eyes to move out of alignment.
Watch as the door moves down and see if they need to be adjusted.

If the eyes are not both lit - they are out of alignemnt or have a wiring problem. try adjusting them and see if the lights come on. - if not check the wiring

Hope this helps

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Ink cartridge, paper & accessories HP Deskjet D2360 Printer - HP Customer Care (United States - English)

Your safety eyes are out of ajustment. Make sure that the eyes are pointing directly at each other. A light will come on on each eye when they are properly aligned. The only other thing that could be wrong is that one of the safety eyes could be bad, and the only thing you can do is replace the eyes. 99% of the time the problem is an alignment issue. By holding down the wall button, you are overriding the safety eyes.

strange, was going to say eyes not aligned but you say they are. try over-riding by holding down wall pushbutton or jumping from red and white terminals. Did you increase down force. Are limit switch terminals moving, If it hits one, it should go back to other,

It has the "Protector System" (safety sensors). chec the sensor indicator light on the receivinng eye the green light had a slight flicker.cleaned both the sending eye and receiving eye lens of dust and cob webs, then realigned the receiving sensor for a steady green indicator light. then check the door function it now works fine.over time, temperature, and viberation the sensors become dirty and get out of alignment, as no one had tampered with the sensor alignment prior to this. Hope this works for you.

door will not go down unless you hold down the inside botton.

If the safety eyes are not connected you need to ho;d the button down until it reaches the close linit.