Liftmaster 3280 limit switch not working

When you close the garage door it doesn't stay shut and goes back up and hits the protector bolt on the track and then stops this means the limit switch is not working here's what I found with mine

[@deepdalal4969]

Thank you for posting this video. All of a sudden the garage door opener was not following the limits and having the same problem. I tried the limit adjuster screws but no change. Then I saw your video and opened up the opener housing and found the problem. The wire you were describing had broke. Fixed the wire and garage door limits started working again and problem solved. You saved me a couple hundred dollars. Thank you!!

[@brucehammer9289]

Thanks for the video. I had the same problem with my 1280R garage door opener. The same wire had broken causing the opener to go beyond its limits and then chewing up the helical gear. The root cause was due to the motor rotating freely in the bracket which put undue stress on the wire harness connected to the RPM sensor. This in turn broke the thinner gray wire from the limit switch. The motor was rotating because all four rubber isolation spacers between the two round mounting plates on the back of the motor wore out. The spacers actually hold the plates together. I replaced these, soldered the wire together, and replaced the helical gear and all was well. Part numbers for the spacers are 41B0139 or 41C556 (~$4 for two) for a 41C4842 motor and bracket assembly. Given the age of the unit, I guess the wearing out of rubber spacers is not surprising.

[@BryanJones1]

So glad I found this! I had the exact same problem. This was exactly the wire that got disconnected. My wire hadn't fallen off but looked like it had ben cut. Weird. But it's fixed now!

[@scottwebber652]

Gotta chuckle on that one. I wonder how many people would have replaced the whole thing. Amazing how some things r such an easy fix !!

[@motocruiser5966]

My down limit switch stops about a quarter of an inch before it makes contact with the other metal piece and the door stops about 5 inches from the floor and then immediately goes back up. I had to adjust the limit switch so that it makes contact right at the exact point the door goes back up so that the door would stay close (with a 5 inch open gap from the floor). I have tried everything to get it to work properly. This all started with a broken spring. I replaced both springs and haven't been able to get the garage door opener to work right ever since. Any ideas on what could be causing this problem?

[@shuvendukumar99]

I want to see how it installed on strong room door. and how it's working

[@coreywittenkeller9158]

awesome video .... my wire broke in half, but your video put me on the solution quick! THANK YOU! big cred to you for making a video to help folks like me out!

[@j.r.g.burritoman5108]

I have the same garage door opener. how do I know if that part is bad? I already replaced RPM sensor and broken gear sprocket. I would appreciate if you could help me. I don't know if I should purchase this part too ..although it's still cheaper than purchasing a whole new unit. Thank you