I have a pretty old garage door. One of the springs broke suddenly today after my wife got home from work. Seems easy enough to fix, I just have no idea how to size a new one or even where to find them.

Hello! Trying to repair a Liftmaster 3850. Issue started with the door opening a foot or so and then closing for a couple of tries, then finally not responding at all. I was told that the flashing error code suggested either the travel module, or I needed a new logic board.

I have two of the identical openers in my garage, so I experimented and swapped the logic boards between each of them - and oddly neither opener would run at all. So, I swapped them back to their original spots and the good opener works fine again but still nothing from the bad one.

So then I replaced the travel module with a brand new one and still no activity. Lastly, I purchased a "tested" used logic board and put it in the bad unit and still won't operate.

The opener powers on, the motion lights respond, but pressing the button to set the travel limits and nothing happens. I can hear a faint electrical noise like it's trying to do something for a second but that's about it. Since taking out the logic board and putting it back in there is no more flashing error code to reference, I just can't get the motor to move the door when trying to set the travel limits. I should note the battery backups are dead so I disconnected them years ago, not sure if that would impact this or not.

Since I have two doors and openers it wasn't critical this get fixed right away so had some fun trying to DIY it and learn a thing or two but I'm about to give up and finally get a new one installed, but is there anything else I missed here?

“UPDATE” thanks to everyone who responded, I’m glad to update this post saying that “yes, it was the sun hitting the sensor in the morning just at the right angle, you guys are amazing, I would have never figure this out by myself thank you guys

Thank you in advance... God bless you sages of modern drawbridges.

I have a new lift master motor (the specific model isn't written upon the unit) and it has a yellow programming button. I have a 878MAX wall keypad. My reading suggests these are compatible (yellow button compatible with 878max keypad). I cannot get it to program. I will list steps taken.

-press yellow programming button on motor unit

-within 30 seconds, type code into wall keypad and hit enter

Variations include...

-pressing and holding enter on the wall keypad

-replacing the 9V battery on the wall keypad

-pressing zero after pressing enter on the wall keypad

-pressing the learn button on the wall button (the one inside the garage) and trying to program the keypad that way

-downloading the myq app just to see if there are in-app solutions (didn't see any)

Further information...

-the motor is successfully paired to two remotes, so it has been able to pair before

-there is no auditory or visual response of any kind of the motor to the keypad

-the receiver wire is hanging down into the garage appropriately

Is it possible to replace this belt? What could cause this? Is this connectors Ned’s to be replaced or belt only?

The cable on the left is catching the door then snapping, is this a quick fix or new door?

I'm sure I'm using the wrong words, but I have a <10 year Chamberlain garage door opener (so I feel it's getting old but not that old). I got it serviced about a year ago when it wasn't working at all and it's been working since then, but in the past couple of months it seems to require me to reset the travel distance all the time. So I learned enough DIY to use the buttons on the opener to set the open level and the closed level, but it seems that the level's wander -- most often so the 'closed' level ends up pushing the door past the ground causing the garage to pop back open. The other way has happen where it's supposedly fully open but it is considerably farther down that it needs to be, so much so that my taller car might hit the so called 'open' door if I didn't pay attention.

When I had to reset the travel once a month I'm like that's ok, I live in a cold environment and its a bit old so it just needs to be handled occasionally. When it became once a week I'm like this could be a problem, and now it seems like every day its slipping a bit. What could be causing this problem? When the problem originally occurred it seems like there was too much slack in the cable after it closed, but nowadays it seems fine when I watch it, the door position just seems to move a lot.

Thanks!