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Chamberlain 5100 Garage Door Opener Problem

Posted by huskerfan44 (My Page) on
Thu, Feb 25, 10 at 13:12

I have a Chamberlain 5100 garage door. It recently stopped working. I removed the housing and it was pretty clear that the drive gear was worn and needed to be replaced. I have since replaced the gear and hooked everything back up. However, as soon as i plug the unit in, the motor starts running and does not stop. It doesn't respond to any of the remotes or wall switches. I've tested it, and since i replaced the gear, the unit will open the door but doesn't stop until it is forced to and then the unit continues to hum.

This problem did not exist prior to changing the gear. Any advice?

Follow-Up Postings:

RE: Chamberlain 5100 Garage Door Opener Problem

What I would do is go back and check every step you took replacing the drive gear. It didn't before but it does now sounds very much like something is not connected right. Check every wire you moved or removed.

RE: Chamberlain 5100 Garage Door Opener Problem

I went back and checked everything. Nothing seems to be out of place. What would cause the unit to turn on as soon as it gets plugged in? Also, when it is plugged in, it doesn't respond to any of the remotes, switches, sensors, etc. What should i do to stop this?

RE: Chamberlain 5100 Garage Door Opener Problem

The only thing I can think of is if the logic board is not plugged in correctly. This shouldn't happen though as it is made to plug in one way only.

RE: Chamberlain 5100 Garage Door Opener Problem

I would be interested to know if the smaller gear on the end of shaft of the gear you replaced is turning the limit switch controls.

RE: Chamberlain 5100 Garage Door Opener Problem

I checked and the smaller gear is not turning the limit controls. It acts like it's slipping. I'll have the smaller gear lined up, but when i plug the unit in the motors starts running and the shaft kind of pushes the small gear away and keeps it from lining up.

I have tried turning the smaller gear by hand to get the limit terminals to touch and the motor still doesn't respond.

My guess, is that it has to be something with the smaller gear though, as nothing else seems to be out of place.

RE: Chamberlain 5100 Garage Door Opener Problem

I have seen this before. On the main gear drive right below the sprocket where the chain goes around, there is a bushing that ceters the main gear drive and that is probably worn out. You may notice a little bit of slack in the chain too. This is caused by normal wear and tear but can accelerated by tightening the chain too much.

Good luck

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