Thursday, August 30, 2018

Garage Door: Fail And Fix

     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.

9 comments:

Anonymous said...

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B said...

You can get a new opener for about a hunnerd bucks.....and they will interface with most new cars and, of course, your smartphone via the innnerweb to allow you to check the status of the door and open and close remotely. Easy to install too.

If you choose to go that route, let me know and I will come install it one of the indy 1500 weekends. Takes about an hour.

Anonymous said...

For supporting things that are unsupported have found electrical tape or epoxy to be good. Epoxy lasts forever - which can be a problem if you want to replace something later.

But this sounds suspiciously like planned obsolescence. Everything still works, but the thing was designed to self-destruct.

Rich in NC said...

In that environment, I've used tie wraps and holes in the circuit board. [YMMV]

Will said...

Since you have already bought the replacement board setup, can you reinforce that portion of the board? Perhaps glue a plastic panel to the other side? I would think that heat buildup shouldn't be a problem, due to random and intermittent use.

Might check the board mounting to the chassis. Might be over clamped/too ridged. Be cautious, though, as sometimes too soft of mounts allows too much bounce or whip of heavy components. This can accelerate the fatigue cycle dramatically. Helps to watch the board/component while running the unit.

Roberta X said...

The board I just replaced had been in service since at least 2007. I figure by the time I have to replace it again, the whole system will want replaced. And I'll be of an age where I'll hire it done.

The issue of a small, heavy transformer hanging by its terminal posts in a high-vibration environment exposed to temperature extremes isn't easily resolved. To make matters worse, the thing runs warm, so I can't glop the whole corner with hot-melt. silicone or "Show Goo" sealant isn't strong enough to help. So I'll let it run its course and see how that works out.

Rich in NC said...

Strategically drilled holes and zip ties. That's the weight/heat/weakness answer.

Norman said...

Remote mount the power supply to a suitable heat sink (such as the bottom panel of the opener's metal housing) with thermal adhesive and run wiring to the board connection point? There may be a source (the Newark catalog?) for a better power supply as well.

Keypounder said...

Agree with Norman, when I encounter this kind of thing, I mount the offending heavy component off the main board, maybe on some perf, and support it better. I don't know whether this can be attributed to deliberately bad design, more likely a case of bean counter design to get it out as cheaply as can be done. In any case, it is annoying when encountered.