Garage Remote Control/Receiver
If your problem is the remote control or receiver, I found a solution that's perfect for me. Last week one of my remotes failed. For a little while it looked like it was the receiver. It turned out to be the remote. If it had been the receiver, a factory replacement would have been about $80 for a new receiver and a second remote for our other car. At that price I was going to replace my 25 year old opener with a new one for $125 when I ran across this device. It's a complete replacement for both the receiver & one remote and it costs less than a single factory remote control unit. It's a "Skylink 318TR Universal In-Car Garage Door Remote Control" The product line is made by a company named SkyLink. It cost me about $22 locally but Amazon has it for $17. It's independent of your existing receiver so, since my receiver is still working with one original remote, I didn't have to buy a second remote. But, a second remote only costs $15. The range may be slightly less, probably because the receiver is mounted lower to the ground, but it has plenty of range for me.
It hooks up to the the wall pushbutton. It's easy to install for anyone who's comfortable with simple wiring like adding a new plug to an extension cord or replacing a wall socket or wall fixture. Note: It can also replace the original remote, but wiring it this way is trickier.