GDO will open but not close.
I have a 1/2 hp GDO from Sears. Model # 139.53646SRT1. It just started acting up. Two remotes and an opener attached to the wall inside the garage. I can open the door from both remotes and the attached opener but when I try closing it from any of them the door will move an inch or two, stop, and the bulb will flash. To get it to close I have to hold down the button on the attached opener (this will not work using the remotes). I did notice the green indicator light on the back of the Unit, next to the SRT button, will flash 4 times and then it is out for approx. 1min. and then flash 4 times again. This is constant. Can anyone help? And... what are the flash codes on this unit?