Craftsman GDO doesn't keep door closed down
Hoping someone can help.
I have a 10(ish) year old chain-drive garage door opener which stopped working from both the remote and the wall switch. When I went in to my local Sears store a lady there told me that it was probably the worm and/or drive gear (and/or other related parts) that had given way and that I should go home, open it up and check whether that was indeed the case. As it turns out, that was indeed the caseÂso I ordered the parts from Sears and installed it this weekend. Surprisingly, I got over the most difficult/time-consuming hurdle i.e. following those not-so-complete-or-idiot-proof instructions and put in all the parts correctly and fixed the GDO back up on the rail/brackets.
When I started to try opening/closing the door, I found that it would not close (and remain shut all the way down)Âi.e. when the door hit the floor, the rail would arch upwards slightly, while the chain would drop/sag downwards almost three inches, and then the door would just start moving back up, and the green LED lights at the back of the GDO unit would keep flashing. There was obviously quite some noise involved as well with this unnatural behavious i.e. the door hitting the floor, the rail arching upwards and the chain falling down.
I tried adjusting all the up/down force thingies but to no avail.
Is there anything IÂm missing, or did/doing incorrectly, or should check for ?
Any help would be appreciated. If this helps, the unit is a Craftsman Â¾ HP one.
Thanks in advance.