Hello there, I have been asked to try to repair a malfunctioning garage door opener. The man who handed them to me said all of the modules work for a few weeks, then suddenly stop working. I opened them, looking for any burnt component, dry solder joints, tested relays in search of a stuck one, but could find nothing. I tested them at home, and they all reliably clicked their relay on and off, as expected. So the question is, what would cause ordinary garage door openers to fail? I thought about a bad powerline (circuits are 50's era in his building, and have never been redone), but have no means to check it. In the same direction, I was looking for a different model garage door opener, and only found two alternatives: one is the run-of-the-mill SkyLink stuff, expensive, reasonably secure, the other is the dirt cheap Chinese-made remotes with no hint about security. Since this is Instructables, I looked for garage door opener projects, but most are so-called "smart" and need a reliable Internet access, both on the smartphone and on the receiver module. Since this is a multi-tenant building and my country is known to be among the most expensive for internet access 1. there's no easily accessible Internet in the garage 2. drivers can't be assumed to have a smartphone and even if they do, 3. Internet access on a cell phone is extremely expensive. The other question would then be: have any of the community members here saw a garage door opener that would: 1- only need easy-to-make RF remotes? 2- be at least as secure as the original SkyLink? 3- require no Internet access?