I will need some information and I will ask you questions that I will need specific answers for. ......sometimes it may be one of a hundred things but together with your patience we can work toward a goal to get this issue resolved.
1-) the make and model of the opener. How old it is. And do you have the manual?
2-) the make and model of the key less
3-) The color of the learn button
4-) do you know where the OPENER motor unit controls are?
5-) has there been any kind of disruption that may have changed the dynamics with this opener....any wiring or perhaps the kids playing there or a recent power outage. What made it go from working to non-working?
6-) if new when you purchased your transmitter did you check for compatibility?
7-) do you feel that you are capable of making simple adjustments and more than mechanical in making some harder ones if necessary?
We can start here and with the info you provide I will add steps toward our target as we proceed by our correspondence
If by some reason a resolution to the problem just isn't possible, I will do my best to supply you with any remaining options, from what other resources I can find.
Please always allow me time to prepare information for you.
And thank you for your help and assistance