Make sure you did not knock a wire off of the start capacitor.

rechecked start capacitor - all wires still connected. looked at circuit board and all looks ok. placed limit switch from this unit on another identical unit and it appears to send the reverse command. reset the opener to the 'down' position by manually backing the limit switch assembly down to the bottom stop. disconnected chain. once again, when wall button pressed, operator ran to top position (door would be in up position if connected) and shut off. when press wall button again, light comes on and unit just clicks. rechecked interruptor cup and it appears to be in proper position (had forgotten it early on in the process). any other ideas? thanks!

I would have to say you have a bad logic board. If everything else is checking out ok and is hooked up fine. I actually ran into this problem the other day, however I knocked a wire off the start capacitor and did not know it. You might try putting a start capacitor in and see what happens, it's a long shot, but the only other option is going to be replacing the opener for that circuit board is probably not available anymore.

I am having this exact same problem. Only, this is the first I have had experience with openers. I have done the troubleshooting portion of manually setting the locator to the bottom (closed) position, then opening the door to the same result. However, I don't know what/where the start capacitor is and how to locate the wiring. What color wire should I be looking for and where is the cap.? What else can I check to troubleshoot, such as the limit switch?

Thanks in advance,

Jeff

Instead of saying you have the exact same problem why don't you list the symptoms. That would help.

Well, rather than a repair, I just moved into our house (3 years old) and the third car opener has never worked right. It initially would go up, but not down, and didn't stop at the top, it just jammed and vibrated against the opener unit. I opened it up to find that somehow the open adjustment stop was bent and the locator just went right by it and kept trying to go up. I righted that situation by bending the stop back and setting the open travel adjustment properly. So now, it will open, and when hitting the stop, does stop. But, it will not close. I can manually close it by removing the belt from the motor and getting everything set at the bottom, then push the button and it opens again and stops properly at the top. Holding down the button does no good, and I can confirm the photo sensors are aligned properly because if I block them, the opener lights come on. It just seems to me that whatever switch exists to tell the opener it is at the top and needs to reverse direction has failed, but I have no idea what that is or how to fix it. I did find the start capacitor you guys were talking about (big blue guy, 4 wires, two red, two blue). My terminals are top and bottom, with connections on each side of it. The reds are on the bottom, and the blues on top. My opener is model 139.53954. Thanks for helping.

Correction, my model is 139.53964. Thanks again for any help.

If is stopping properly now and will not do anything when you try to close it, I would imagine the problem would be in the logic board. If I were there I would visually inspect all the wiring and make sure the pin connector is plugged in tight to the logic board, then I would try a logic board and see what happens. Sorry, this is not a problem I frequently deal with.

That's alright. I appreciate the help. I think I will try taking the logic board from the other door and plugging it into this one to see if that is the issue (before spending the $80 for a new one).

The problem I seem to be having is that the door operates normally under no-load conditions but as soon as I attach the door, the door will only go down a couple inches and stop. The light will blink as though the door had been stopped by an obstruction. I adjusted the door travel strength to the maximum setting with no change.
Does the door travel strength have anything to do with the motor capacitor ( the capacitor delivers more power to the motor as required )or has the PC board failed?

My garage door opener hums but works find. I just can not stop it from humming