Sears garage door opener will not open or close all the way
I just moved into a house and the auto garage door will not work properly. There are no remotes and I can't find the sensors. It seems that this door was installed without sensors. Anyway the door will only open a few inches and then closes. When I open it manually and try to close it with the button on the wall the door moves a few inches and stalls. If I keep pushing the button it will close and sometimes open. It is an old unit Sears/Craftsman 1/2hp unit. Can anyone help?