I wondered why my garage remote didn\'t work....

[Sylvia Else]

So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

 

[John Robertson]

On 2022/08/01 10:34 p.m., Sylvia Else wrote:

So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#

 

[Lasse Langwadt Christensen]

tirsdag den 2. august 2022 kl. 08.01.31 UTC+2 skrev John Robertson:

On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.
This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).

leaded solder is fine (and easier) for rework

 

[Sylvia Else]

On 02-Aug-22 4:01 pm, John Robertson wrote:

On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#

Glue wouldn\'t hurt.

But if anything was going to fall off, I\'d have thought it would be the
tactile switches.

Sylvia.

 

[Clive Arthur]

On 02/08/2022 08:06, Sylvia Else wrote:

On 02-Aug-22 4:01 pm, John Robertson wrote:
On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#

Glue wouldn\'t hurt.

But if anything was going to fall off, I\'d have thought it would be the
tactile switches.

Sylvia.

Maybe the switches are supported at the top by a membrane or buttons?

Is it possibly the battery could move enough to touch the Xtal?

--
Cheers
Clive

 

[Clifford Heath]

On 2/8/22 17:06, Sylvia Else wrote:

On 02-Aug-22 4:01 pm, John Robertson wrote:
On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#

Glue wouldn\'t hurt.

But if anything was going to fall off, I\'d have thought it would be the
tactile switches.

I\'ve seen something like this. I think the crystal has the highest
thermal mass (or lowest thermal resistance on its legs) of any SMD part
on the board (the battery tabs are through-hole) and the solder reflow
wasn\'t quite hot enough for long enough, so it got glued down by melted
flux not melted solder, or the solder remained only sintered so it was weak.

CH

 

[Ricky]

On Tuesday, August 2, 2022 at 3:06:19 AM UTC-4, Sylvia Else wrote:

On 02-Aug-22 4:01 pm, John Robertson wrote:
On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#
Glue wouldn\'t hurt.

But if anything was going to fall off, I\'d have thought it would be the
tactile switches.

No reason for the switches to fall off. They are always being pressed ONTO the board.

The crystal solder probably was cracked when it was dropped at one point, but it kept working until both joints failed.


--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Phil Hobbs]

Sylvia Else wrote:

So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

Looks like it might have got whacked by the battery when you dropped it
on the floor.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[legg]

On Tue, 2 Aug 2022 15:34:00 +1000, Sylvia Else <sylvia@email.invalid>
wrote:

So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

Probably knocked around during battery replacement.

RL

 

[Rocky]

On Tuesday, August 2, 2022 at 7:33:58 AM UTC+2, Sylvia Else wrote:

So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

The pads on the PCB look dull. As Clifford suggested, maybe the soldering was poor - at least on the crystal. The other joints are bright and look good.

 

[Ricky]

On Tuesday, August 2, 2022 at 6:39:30 AM UTC-4, Clifford Heath wrote:

On 2/8/22 17:06, Sylvia Else wrote:
On 02-Aug-22 4:01 pm, John Robertson wrote:
On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#

Glue wouldn\'t hurt.

But if anything was going to fall off, I\'d have thought it would be the
tactile switches.
I\'ve seen something like this. I think the crystal has the highest
thermal mass (or lowest thermal resistance on its legs) of any SMD part
on the board (the battery tabs are through-hole) and the solder reflow
wasn\'t quite hot enough for long enough, so it got glued down by melted
flux not melted solder, or the solder remained only sintered so it was weak.

Looking at the image in detail, it would appear you are right. The solder doesn\'t look broken to me, it looks like it molded around the contact, but never was a good solder joint. It probably never really wetted the crystal contacts.


--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Ricky]

On Tuesday, August 2, 2022 at 8:55:16 AM UTC-4, Rocky wrote:

On Tuesday, August 2, 2022 at 7:33:58 AM UTC+2, Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.
The pads on the PCB look dull. As Clifford suggested, maybe the soldering was poor - at least on the crystal. The other joints are bright and look good.

My understanding is the bright/dull thing went away with lead free solder. I was shown photos from some document IPC maybe, that showed the most horrible, grainy solder joints as examples of good joints! Hard to tell from the crap joints.


--

Rick C.

-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209

 

[Fred Bloggs]

On Tuesday, August 2, 2022 at 1:33:58 AM UTC-4, Sylvia Else wrote:

So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Crystal leads were not plated adequately with compatible alloy/metal (copper/silver or alloy) to make a good solder joint, or the part was not stored properly in manufacture and corrosion or oxidation on the leads took place before being soldered to the board. You can\'t make a proper solder joint between any old combination of metals. It\'s definitely a bad solder joint. Shock effect is not a possibility because a proper joint will tear the board pads off and/or show visible damage to the component before it lets loose.

Sylvia.

 

[Fred Bloggs]

On Tuesday, August 2, 2022 at 6:39:30 AM UTC-4, Clifford Heath wrote:

On 2/8/22 17:06, Sylvia Else wrote:
On 02-Aug-22 4:01 pm, John Robertson wrote:
On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#

Glue wouldn\'t hurt.

But if anything was going to fall off, I\'d have thought it would be the
tactile switches.
I\'ve seen something like this. I think the crystal has the highest
thermal mass (or lowest thermal resistance on its legs) of any SMD part
on the board (the battery tabs are through-hole) and the solder reflow
wasn\'t quite hot enough for long enough, so it got glued down by melted
flux not melted solder, or the solder remained only sintered so it was weak.

CH

That\'s close but you would think they have all that ironed out after making gazzillions of fobs...

 

[Joe Gwinn]

On Tue, 2 Aug 2022 08:32:45 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

Looks like it might have got whacked by the battery when you dropped it
on the floor.

That would be my guess as well.

Joe Gwinn

 

[Ricky]

On Tuesday, August 2, 2022 at 9:32:39 AM UTC-4, Fred Bloggs wrote:

On Tuesday, August 2, 2022 at 6:39:30 AM UTC-4, Clifford Heath wrote:
On 2/8/22 17:06, Sylvia Else wrote:
On 02-Aug-22 4:01 pm, John Robertson wrote:
On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#

Glue wouldn\'t hurt.

But if anything was going to fall off, I\'d have thought it would be the
tactile switches.
I\'ve seen something like this. I think the crystal has the highest
thermal mass (or lowest thermal resistance on its legs) of any SMD part
on the board (the battery tabs are through-hole) and the solder reflow
wasn\'t quite hot enough for long enough, so it got glued down by melted
flux not melted solder, or the solder remained only sintered so it was weak.

CH
That\'s close but you would think they have all that ironed out after making gazzillions of fobs...

That\'s not the way commercial devices work. They make them and keep making them the same way until something forces them to change it. The fact that someone broke their keyfob by dropping it, is not material to them.

Besides, we haven\'t seen the case. I\'m willing to bet there is a barrier that prevents the batter from contacting the rest of the electronics.


--

Rick C.

-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209

 

[server]

Sylvia Else <sylvia@email.invalid> wrote in news:jkrra0Faji0U1
@mid.individual.net:

> https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

You can blame RoHs for that. Shitty lead free solder joints nowadays
get inspected as passed, even when grainy and full of micro-fractures.
Likely a bad plating on the part legs as well. Does not look like it
would take many jolts to tear free from the pads.

Those two tiny pads can be re-soldered with 63/37 tin lead solder and
it will be reliable. It is allowed for servicing. Use a flux pen to
wet the pads after you have braid-wiped the them to remove the previous
solder remnants. Clean up the legs of the part too, but only a quick
reflow cleaning as it will introduce heat into the part directly.
Actually the legs look clean enough, maybe look at the bottom side of
the legs to see if the cladding remained on the board. If so, a re-tin
is needed and just hope the heat does not cause an internal detachment.

 

[server]

John Robertson <spam@flippers.com> wrote in
newsDidndcQqqY_IHX_nZ2dnZfqnPqdnZ2d@giganews.com:

On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#

Most labs doing service on RoHS lead free assemblies are permitted
to use 63/37 Tin Lead solders on lead free board for the repair.
This includes Europe\'s rules, not just the US.

Reflow assemblies use lead free OK, but in a repair lab, getting a
non-grainy connection is not as easy, so most techs use the old tried
and true and the rules for RoHS allow it.

 

[server]

Clifford Heath <no_spam@please.net> wrote in
news:170780f29fb86497$1$1950103$e2dde862@news.thecubenet.com:

On 2/8/22 17:06, Sylvia Else wrote:
On 02-Aug-22 4:01 pm, John Robertson wrote:
On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#

Glue wouldn\'t hurt.

But if anything was going to fall off, I\'d have thought it would
be the tactile switches.

I\'ve seen something like this. I think the crystal has the highest
thermal mass (or lowest thermal resistance on its legs) of any SMD
part on the board (the battery tabs are through-hole) and the
solder reflow wasn\'t quite hot enough for long enough, so it got
glued down by melted flux not melted solder, or the solder
remained only sintered so it was weak.

CH

Good analysis. Lead free is a hotter reflow, and cost cutting
makers spool up their reflow ovens as fast as they can get away with.

It may have soldered, but the part legs might have poor
plating/cladding choices made by the maker as well.

The pads do look like they did not quite reach good reflow temp
though.

Use 63/37 to fix. And glue... hot melt should be fine. A dab on
each long edge.

 

[server]

Ricky <gnuarm.deletethisbit@gmail.com> wrote in
news:bbc8438b-47dd-456e-b075-fdb5f5f3052dn@googlegroups.com:

On Tuesday, August 2, 2022 at 3:06:19 AM UTC-4, Sylvia Else wrote:
On 02-Aug-22 4:01 pm, John Robertson wrote:
On 2022/08/01 10:34 p.m., Sylvia Else wrote:
So I opened it up.

https://www.dropbox.com/s/4qb9x10tnczm3x8/remote.jpg?dl=0

Seems fairly clear what the problem is.

By why would the crystal fall off the board like that?

Sylvia.

This sort of item should also be secured to the PCB with glue.
Easy to resolder if you have some lead-free solder (I assume).
John :-#)#
Glue wouldn\'t hurt.

But if anything was going to fall off, I\'d have thought it would
be the tactile switches.

No reason for the switches to fall off. They are always being
pressed ONTO the board.

All the more reason to fall off. You seem unfamiliar with \"solder
creep\". Even the axis they get impinged on contributes. They more
likely simply did solder up right in reflow, whereas these two legs
did not. One countertop drop is all it takes. And the switches then
recieve the same side forces then as well.

The crystal solder probably was cracked when it was dropped at one
point, but it kept working until both joints failed.

Looks more like a single event detachment to me.