The automatic garage door has been acting...odd. It was stopping randomly during the closing cycle -- it would stop, the lights would go out, and it would do nothing for a few seconds. I thought it was either bad contacts on a relay or the motor was stalling, and planned to check it out this coming weekend.
Yesterday, it failed badly on Tam; she got it to shut but when I left, later, it balked opening and closing. So I called in the experts and they showed up this morning.
It's not a relay. It's not a mechanical issue cause the electric motor to flake out on excessive torque. Nope it's a tiny, designed-in flaw, one that took the overhead door tech about five seconds to find: the power transformer is soldered to a circuit board, and hangs from it in one corner. Over time, the solder joint and foil in the very corner breaks, and you've got an intermittent board. Often, the substrate cracks as well: heavy transformer, inexpensive circuit-board material. Repair is iffy, since the thing's already stressed and you're just slopping on more solder. Not usually stocked, since it's an older board, and about two weeks lead time. I resoldered the bad joint (it was sure-enough broken) but it was pretty ugly, and by the time I was back up from the basement, the tech had found a new replacement board on his truck.
Not cheap, in the way repair at the whole-board level usually is costly, but it's working and perhaps I'll get another ten years or more from it.
Working On A Starship
1 month ago