Can a crystal break?

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cmartinez

Joined Jan 17, 2007
7,744
My garage opener's remote has been dropped many, many times throughout its long history ... and every time that's happened it split into three pieces: the pcb, and its two plastic lids...

Well, it seems that I've dropped the darned thing for its last and final time ... when I put it back together, it stopped working and now the garage door won't open anymore unless I manually press one of the buttons at the motor's unit. Even when the tiny LED light blinks when the proper button is pressed, the motor does not detect the signal and fails to open

3caf8b54-eea1-4788-b202-7296852ec20c.jpg

I've closely inspected the circuit and there seem to be no dry contacts nor broken traces in it. What's more, I heated my soldering iron and pressed it against every pin in every component to make sure that effective contact is being made in every node.

Question, is it possible that the device's crystal was damaged somehow by the impact? Because that's the only possibility that I can think of for it to have stopped working the way it did.

NOTE: The other side of the board contains only its cr2032 battery, which is brand new btw.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
7,744
It is very possible. I have broken several crystals in R/C receivers by crashing the planes they were controlling. A crystal is just a very thin sliver of quartz or ceramic material with a metalized coating on each side. They are very fragile.
The engraving on the crystal reads "A09.843TE1AB" ... gonna look it up
 

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cmartinez

Joined Jan 17, 2007
7,744
Theoretically - YES.
Check oscillation by oscilloscope.
Which pin? :oops: ... just kidding ... I'm going to attach the clip to the circuit's ground and then test every single pin of the darn thing and see if any of them produce a 9.843 MHz square wave ...
 

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cmartinez

Joined Jan 17, 2007
7,744
OTOH, what would happen if I were to probe the circuit's antenna? Should it produce some sort of wave or would the signal be too weak for the oscilloscope to react? ... sorry, but this is the very first time that I'm about to work on an RF circuit in my life and I'm not sure about what to do nor what to expect ... no kidding
 

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cmartinez

Joined Jan 17, 2007
7,744
Try shaking the circuit board gently. Quite often it is possible to hear the broken crystal rattling in its metal case.
just tried it, but no... I can't hear a thing ... either way, I've already bought a crystal from Mouser for one buck ... gonna replace it as soon as it gets here. And if that doesn't work, well it was about time I replaced the darned system with something that I can control from my smartphone anyway.
 

KeithWalker

Joined Jul 10, 2017
2,403
just tried it, but no... I can't hear a thing ... either way, I've already bought a crystal from Mouser for one buck ... gonna replace it as soon as it gets here. And if that doesn't work, well it was about time I replaced the darned system with something that I can control from my smartphone anyway.
Have you considered the inconvenience of having to wake up your phone, find the app and open it while you are driving into your driveway? If I couldn't fix it, I would replace it with something similar to the old one.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
7,744
Have you considered the inconvenience of having to wake up your phone, find the app and open it while you are driving into your driveway? If I couldn't fix it, I would replace it with something similar to the old one.
I have ... but then there's google's speech commands which I've been using for a while... very agile and convenient if I may say...
 

strantor

Joined Oct 3, 2010
5,971
I have ... but then there's google's speech commands which I've been using for a while... very agile and convenient if I may say...
"Hey wiretap, open my garage." Doesnt get much easier than that.

Oh wait, yeah it probably does. My new thermostat has a feature that if enabled monitors my phone location and turns the temperature down on during my commute home, whether I leave work early or late. I don't use the feature because there is always someone else home. I would be surprised if modern garage door systems don't have a similar feature. I wouldn't want my garage door opening half way through my hour long commute, but it would be cool if it would start opening at just the right distance from the house that I'm pulling through the door right as it reaches the top.
 

MisterBill2

Joined Jan 23, 2018
12,399
Not only can the quartz element in a frequency control crystal break, it can also be knocked loose from it's mounting points. so destruction by shock is certainly possible.

It might also be that one of the plated thru holes is damaged on the PCB,
It seems the frequency is 9.843Mhz, some overtone, third and fifth are most common.
 
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MaxHeadRoom

Joined Jul 18, 2013
25,469
My garage opener's remote has been dropped many, many times throughout its long history ... and every time that's happened it split into three pieces: the pcb, and its two plastic lids...
I had one old garage door that I could not get parts for so I got this of Ebay, ~$8.00, I wired the relay to the GD manual terminals to simulate local opening.
The Key ring fob is a bit sturdier.

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MisterBill2

Joined Jan 23, 2018
12,399
Those steps are unnecessary if you're texting while driving like most people today.
View attachment 269313
Texting while driving is dangerous, and it is even worse than drunk driving, because at least the drunk may be trying to pay attention, while the texting person is focused on their phone.
The fact remains that driving requires the driver's attention. Some folks are just lucky, and luck often runs out at inconvenient times. Fortunately I have been able to avoid those drivers, so far, but it does get old having to watch out for those who are not paying attention to driving.

But we have gone far off topic here.
 

Ian0

Joined Aug 7, 2020
5,504
"Hey wiretap, open my garage." Doesnt get much easier than that.

Oh wait, yeah it probably does. My new thermostat has a feature that if enabled monitors my phone location and turns the temperature down on during my commute home, whether I leave work early or late. I don't use the feature because there is always someone else home. I would be surprised if modern garage door systems don't have a similar feature. I wouldn't want my garage door opening half way through my hour long commute, but it would be cool if it would start opening at just the right distance from the house that I'm pulling through the door right as it reaches the top.
Just wire the transmit button permanently on, as soon as you get within the transmitter’s range of the door, it will open!
 

shortbus

Joined Sep 30, 2009
9,441
Don't know the brand or age of your opener, but after working on the remote did you re-link it to the opener? Most of the older ones you had to do this, even car door remotes when being replaced have to get linked to the car before they will work.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
7,744
In case you were wondering ... my conclusion is yes ... a crystal can indeed break!

I know that for a fact now because a few minutes ago I received a new crystal that I ordered from Mouser, and changed it for the one that I presumed damaged.

Lo and behold! ... the remote started working immediately after that! ... no sweat :)

Thanks all who participated in this thread and helped me fix this annoying nuisance. And to answer your question, shortbus, no, I didn't have to re-link the opener. The remote is a very old one and has none of that sophisticated security of the newer ones.
 
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