I have a 20-year-old Python Garage door opener. Worked fine.
I decided to add an additional "push-button" dry contact relay to the mix so I could operate it with my phone. After unplugging it, I hooked up the wires (22-guage stranded security wire) and tested it and it wouldn't operate.
After other tests, I tried shorting the two screws with a short wire. No joy.
The car (RF) remote works fine, so the safety sensors must be working.
I did this to an identical opener (I have three...) and it worked fine.