Garage door opener issues

jcummins · Jul 10, 2020

I'm no stranger to garage door openers. I've installed them in just about every house that we've moved into that did not have them and there's been several. I've also rebuilt several was new parts. But I've always been able to see the obvious problem. Now I've got an issue and I can't identify the problem.

This is a Chamberlain 41A5021. Probably 20 years old. I've lived here for 10, and replaced the plastic gears ect once. This is on my barn with a 14 by 11 overhead door. Going up or down it doesn't matter it's simply will move a little bit then stop and reverse. The problem is not with the door I've unhooked it from the trolley and worked it with out the door attached and the problem persist. The problem originally was very intermittent but now it's got to the point something needs to be done. The problem has something to do with the rpm sensor. It was acting up pretty bad and I held my finger on the sensor to make sure it's straight with a rotating cup and it seemed to work better so I cable tie the thing in place pretty securely and for about 2 or 3 days it work fine and now it's back to the same problem. Tempted to buy a new RPM sensors, they are not expensive at all but I just hate throwing parts at something when you don't know what the problem really is. And it may have been luck that I got the door to working right by messing with the rpm sensor and it may have nothing to do with it at all.

I know they're smarter people than me on this board hoping somebody can give me an idea what to do.

lilranch2001 · Jul 10, 2020

I have a very similar issue, I hope to see what advise is gleaned from here.

Mine does not happens every time, sometimes it stops about 18 " on uptravel and stops, and sometimes stops on down travel the same amount and reverses

JPRambo · Jul 10, 2020

On some models there is an up and down tension adjustment. And an adjustment for up and down travel.

jcummins · Jul 10, 2020

I've messed with that. With it doing this without the door attached, it's more than that.

kirkawilson · Jul 10, 2020

I had a wiring issue on one side of the laser circuit (reversing sensor) that was difficult to diagnose. I would say that if you have tested your reversing sensors and they stay aligned properly during travel, your rpm sensor is a good guess.

jcummins · Jul 10, 2020

Yes the door sensors a broken wire any number of things I guess could cause this and that's what makes it so difficult to come to grips with. Then you have the circuit board itself which may have some kind of issues. But since I move that RPM sensor and it seemed to impact how it performed it's my best guess at this point to and I may just go ahead and order it.

i7win7 · Jul 10, 2020

If it happens in both directions, does motor have a force adjustment on it?
Chain drive? may have a rusty link that doesn't flex right.
Without door, motor and drive seem to be the problem, clean door reversing sensors could be too dusty.

crreed67 · Jul 11, 2020

I have basically the same setup as you and had the same problem. After trying everything like you I re-aligned the electric safety eyes at the bottom that shoot across to each other like others have mentioned and it's been fine ever since. May not be your problem but it's an easy check/fix.

grsthegreat · Jul 11, 2020

Since it happens without door attached, im thinking the door sensors are at fault. I had a genie opener that did that. Messed with everything i could until i just decided to try replacing the 2 safety sensors... bingo. 2 years now no more issues. If you HOLD the open/close button mounted on the wall CONTINUOUSLY, will the unit operate properly while trying to close...some units use continuous hold as a sensor bypass.

Then again...i doubt the sensor would cause door not to open.....but not sure