Garage door opener problem

[thool]

I have a Craftsman (Chamberlain) model 139.53918D that started misbehaving a couple days ago. When I hit open from a remote or from the wall switch, it opens a few inches then stops. Press again and it closes real hard and binds (the track bows up under tension). Then it just stays in this state: subsequent presses just adds tension.

I went through the entire limit and force procedures three times, with 30+ minute unplugs between to clear any bad states. It works for an hour or so after reprogramming, then goes back to its broken condition.

It was purchased in 2012 and I installed it myself, worked perfectly until a couple days ago. No power surges that I know of, outlet is good. I suspect the motor and position sensor, but want to get other opinions before dropping $70.

Any advice? I'd hate to buy the wrong part almost as much as I'd hate to buy a whole new opener.

 

[cbogg]

Call Chamberland, they should be able to help you figure this out. They know their stuff better than we do. Sounds like a sensor to me but I'm not putting my money behind it.

 

[Doorguy]

The motor has a lifetime guarantee on it and I doubt thats it. It sounds like the RPM sensor may have gone bad or I seen where they have fallen off the motor shaft. Take the cover off and have a look inside for anything that might look out of place. Please pull the power plug first.

 

[thool]

I'll take a look this week, and also give Chamberlain a call. I've never been inside an opener, but it looks kind of simple from the parts diagram.

 

[upndown]

Have you tried the door manually? If it's shutting off during the open cycle, could be something as simple as a broken spring. They are designed to shut off when trying to lift to much dead weight.

 

[thool]

The door works fine when disengaged from the trolley. Easy to move in both directions and no binding. Both torsion springs are intact.

 

[thool]

Update...

Called Chamberlain and they said likely the motor with travel module.

Took the head unit down, disassembled, and found on the end of the motor a plastic "module" with a small wiring harness. Took that off and noticed debris (grass particles from a bird nest attempt) in and around it. The gearbox opened easily, and appeared to be a rev counter with a couple optical pickups and slotted wheels. Wouldn't surprise me if a couple grass particles threw off the sensors. Blew it and the entire innards with compressed air and it seems to be working again. Took about 2 hours.

***** that if the travel module is bad, you have to buy the motor too. Another option I guess would be to buy a similar head unit off CL and try the module.

We'll see how this goes.

 

[ghlkal]

Interesting issue ...

Thanks for taking the time to post the follow up

 

[gnpenning]

See post 3

 

[thool]

See post 3

Yeah, saw that. It was absolutely connected to the motor shaft, and nothing seemed to be out of place. The wheels have some play, so it might just be wear?