Garage door stops working, lights work fine. When opener is unplugged and plugged back in it starts working fine for a few days then stops working againg until power cycled.
Probably a bad controller board - whether the better option is a new controller board (lower cost, generally no guarantee) or a new garage door opener (comes with a guarantee) is a call you'll have to make. Put a surge suppressor on the outlet feeding it - they are highly computerized these days.
Given the evidence of damage/malfunction, you should also test the operation of the safety devices - does the door stop and/or reverse when the "electric eye" sensor beam is broken while it's closing, and does it stop AND reverse if it hits a 2/4 laid flat (a 1-1/2" thick obstruction) laid on the floor when closing? If not, you should definitely disconnect it and replace either the controller board or the whole opener ASAP - with the safety devices malfunctioning, garage door openers do kill people, children, pets...
The opener I have replaced the controller on operated nearly normally, but I noticed that it was trying to drive the door through the floor of the garage after it was done closing, and when trying to adjust that I noticed that it no longer passed the safety tests above. Lightning had struck a nearby tree and evidently caused enough of a surge to damage the controller.