Garage Door Opener Only Goes 1' then Reverses After Repair

[Bzowk]

Good Afternoon, All -

Starting a couple of weeks ago, whenever the garage door opener was activated; you could hear it but nothing would happen to the door. After looking into it, I found that the gear shaft cleanly broke right below the top sprocket that moves the chain. I ordered a replacement part from Amazon and have invested most of the day into it.

I successfully disassembled the unit, replaced the part, and reassembled everything; but it's not working correctly. Whenever I press the button to activate the opener, it moves the door about 1 foot then reverses in a matter of a couple of seconds. I verified that everything was correctly reassembled and compared pictures I took prior to working on it and don't see anything out of place. Below is the mode I have as well as what else I've tried after searching online:

Model
Chamberlain (Residential)
Model: 7520D
1/2HP 120V / 6Amp
Mfg Date: 06/13/05

Troubleshooting Attempted
- Verified the safety sensors are working and beam not broken
- Verified that garage door moves up & down easily
- Removed chain, moved door from closed to open position, reattached chain and tried again
- Verified that the carraige assembly is adjusted correctly, not obstructed, and moves with the opener
- Adjusted open / close force testing max and min levels (no difference)
- Verified wire connections for sensors was secure & tried reversing them

If you have any suggestions, it would be a huge help. Thank You!!

 

[BeeTheBPc]

Have you tried lubricant?
We replaced the motor with a more powerful one still had an issue so we bought some lubricant which improved but didn't fully fix the problem. Also one of our remotes isn't working. I think they're still under guarantee so might start with that. Sorry, not a lot of help. Best of luck.

 

[frogspawn321]

Good Afternoon, All -

Starting a couple of weeks ago, whenever the garage door opener was activated; you could hear it but nothing would happen to the door. After looking into it, I found that the gear shaft cleanly broke right below the top sprocket that moves the chain. I ordered a replacement part from Amazon and have invested most of the day into it.

I successfully disassembled the unit, replaced the part, and reassembled everything; but it's not working correctly. Whenever I press the button to activate the opener, it moves the door about 1 foot then reverses in a matter of a couple of seconds. I verified that everything was correctly reassembled and compared pictures I took prior to working on it and don't see anything out of place. Below is the mode I have as well as what else I've tried after searching online:

Model
Chamberlain (Residential)
Model: 7520D
1/2HP 120V / 6Amp
Mfg Date: 06/13/05

Troubleshooting Attempted
- Verified the safety sensors are working and beam not broken
- Verified that garage door moves up & down easily
- Removed chain, moved door from closed to open position, reattached chain and tried again
- Verified that the carraige assembly is adjusted correctly, not obstructed, and moves with the opener
- Adjusted open / close force testing max and min levels (no difference)
- Verified wire connections for sensors was secure & tried reversing them

If you have any suggestions, it would be a huge help. Thank You!!

Is there a plastic oblong shaped block at the bottom of the door ? If this contains batteries, they may need to be replaced.

 

[[email protected]]

I have electric roller doors on my garage, about a foot from bottom of the door frame is a magnet fixed inside a plastic clip, if the magnet is missing/ lost the door will open to the height of the magnet and close again. The sensor on the bottom of the roller door detect to magnet and allowed the door to fully open.
I have lost several magnets from the door frame over the years and always have the same problem as you have. I have bought replacements on the internet.

 

[diyer999]

POSSIBILTIES: I read what you tried, it seems like just about everything. Usually when they reverse they sense an obstruction, but you said there is none. Go to You Tube generally and with your brand and model, Some good info there.