Before you replace the opener, make sure your door is still working properly.

You should have some kind of manual disconnect of the opener from the door (sometimes a red rope dangling). Once you've confirmed you've disengaged the opener, with your hands try to lift the door up. It should be pretty easy. This should not be a struggle at all. Now try to pull it down. That too should also be easy and little muscle effort. You shouldn't need to exert much force either way because the springs on your door do most of the work.

If it is hard to lift either way, you have a door (or more likely spring) issue. Replacing your opener won't fix your problem. Get garage door service. Also, if you aren't REALLY REALLY experienced with garage door springs, don't mess with them. There is a tremendous amount of force stored in them, and if you do it wrong, all that energy will come out and once and could maim or kill you. Garage door service doesn't have to be crazy expensive. A couple hundred dollars is what it cost to have my springs replaced (parts included) a year or two ago.

Don't take chances with your life.

It might not be the door opener. The door/springs/track may just need adjustment.

I would call your local hardware store and ask for a recommendation for a "garage door guy". Then follow his advice.

Be VERY careful with garage door springs! They can kill you. Torsion springs especially.

Chamberlain has an almost monopoly in this market.

Keep in mind that their “smart” openers do not integrate well with Siri, HomeKit, Homebridge, or similar platforms. They want you to use their app, so they can show you ads.

The spring can kill you. Self repair and installation has potential to be rather treacherous.

Assuming you are asking for installation advice, please consider hiring a professional. I am no stranger to diy projects and thought I could adjust and fix mine on my own and ended up snapping the spring. I tried to figure out what to replace it with but ended up calling out a professional. The door now works far better than it ever did and I know I could not have done as good a job.

My brother did overhead garage door install and repair for about 20 years. He will be the first one to tell you stop screwing with it. What might be a minor cost if you call right now could be a major cost if you keep screwing with it. He seen cases where had they called right away. It would have been the service call, plus a couple hundred dollars. Service call meaning trip charge.

Because they kept screwing with it it was a very large bill. If I remember right, the worst one was where he had to replace tracks, garage door opener, and I think there was even a panel he had to replace.

Another person said you can check the tracks to see if there’s something in it but beyond that. I'd just called a professional.

You may just need to adjust the sensitivity of the safety reverse on the door, but to reiterate what everybody else is saying, working on garage doors tends to fall squarely into the camp of "if you have to ask, you need to hire a professional". I do a lot of DIY around my home the garage doors are something that I won't touch for anything but the most basic adjustments.

It's probably just the springs. Take a look at them and visually see if any are broken. Just don't mess with them, they can be deadly.

I had a garage door company service mine last year. It was about $200 bucks to get a new spring installed.

Can you clarify what style of garage door this is? I'm aware of two main styles: 1) a one-piece door which tilts upward, kinda like a doggy door, and 2) a door with four horizontal panels that rolls straight up on tracks. The first type has giant springs on the left and right, whereas the latter has an axial spring situated just above the door.

In both garage door styles, it should be the case that once the opener is disconnected, the door can be manually lifted and opened, to get the car out during a power cut. If this is not possible, something is wrong and the door itself needs to be serviced first, to avoid cascading issues.

If you do replace the opener, consider models which have a small backup battery, to operate when there's a power cut. The door must still be in working order, but the battery will slowly open the door using the remote control, as normal. Some openers have WiFi connectivity -- which I think is mostly a gimmick, except if there's an app to indicate if I've closed the garage door or not.

Your stops are kicking in. Check the rollers and track, it's binding or there's something in it.