You’ve gotten some pretty good info here so far. The thing that usually fixes my problem is often as simple as shutting down the device, unplug it from the wall, wait about 30 seconds, plug it back in, & then restart the device so it boots from ground zero. This often fixes the problem. In 20 years, I’ve only had to have a tech out once & that was when a stalker jerked the incoming cables away from the connection box. They had to replace almost all the cables to fix the problem & I wasn’t handy enough to do that job. The shutting down, unplugging, waiting, plugging back in & the restart seems to fix 99% of my problems even without having to call the company at all!!!