I wondered why my garage remote didn't work.

On Tuesday, August 2, 2022 at 10:42:15 PM UTC-4, Sylvia Else wrote:
> On 02-Aug-22 3:34 pm, 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.
> OK, I've soldered it back, and it works. It remains to be seen whether 
> my soldering is better than the original. 
> 
> The most difficult aspect was getting it back into its enclosure, which 
> seemed to be designed for assembly in zero-g, by someone with five 
> hands, or something. 

That's where they get the lowest labor rates.

-- 

Rick C.

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

Sylvia Else <sylvia@email.invalid> Wrote in message:r
> On 02-Aug-22 3:34 pm, 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.OK, I've soldered it back, and it works. It remains to be seen whether my soldering is better than the original.The most difficult aspect was getting it back into its enclosure, which seemed to be designed for assembly in zero-g, by someone with five hands, or something.Sylvia.

It probably dislodged from thermal cycling.  Common problem in the
 auto industry.

Cheers
-- 


----Android NewsGroup Reader----
https://piaohong.s3-us-west-2.amazonaws.com/usenet/index.html

Clifford Heath <no_spam@please.net> 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.

Correct. This is a common problem with larger parts, like coin cell 
holders etc. They need more time to heat up so you don't get a cold joint.

I had a digital clock made by a PCB assembler that I got for free at some 
trade show. Something fell off and I told them about it at the next show I 
ran into them at and they actually offered to RMA and repair it for me as 
they were embarassed about it.