you have all kinds of crazy soldering
irons and microscopes and you know very
fine tools that you're using to do this
right this seems like an incredibly
intimidating thing it does seem like
that but it's it's really not you know
and I would say that that not every
component is feasible to replace you
know it's technically replaceable but
it's not feasible you know on a on a
board like like an iPhone you know in
specific or even this one like if we
kind of look really closely at this
board you can see that there's like a
black glue looking stuff right apples
been using that more and more yes and
this stuff is called underfill and it
kind of makes sense from a design
perspective that as things get smaller
and you're trying to like fit more
complexity into a tighter package that
you do more use more of these sort of
ball grid array chips we're just talking
about now those guys have to sit on the
sort of array of these spheres you know
balls that have to make contact with
both the board and the chip so if you
imagined dropping that phone you know on
the sidewalk it would be really easy to
kind of just get one little crack that's
what killed the xbox 360 the red ring of
death is caused by cracks and the ball
grid array on the graphics chip and they
just stopped working well we'll have to
fight about that later okay so but the
that knee of that that is a really
important topic I think you know this
this idea of chip failure and what to do
about it because it really influences
repair repair so like BGA chips that are
dropped absolutely what you just said is
totally true you could get a cold joint
you know if you drop it but people don't
really drop the xbox and I don't really
drop the Mac look that much you know so
what happens is you can have a failure
of the chip itself so the the inherent
chip the silicone wafer that the thing
is made out of can fail and it does feel
it feels because of heat in the iPhone
happens all the time the iPhone 5s
you're gonna have fail
the u2 IC chip that controls the
charging logic not because of a drop but
because of actual failure of the chip
itself
yeah an over-voltage can just damage it
right so knowing sort of the history of
the of the device really helps guide
your repair so for a PlayStation that
has a graphic problem it's probably not
at cold solder joint if you have the
same you know an iPhone 5s that was
dropped it probably is a cold solder job
yeah
and so there's this whole like you know
big fight out there about you know how
do we address BGA failures and there's
you know a lot of you know folks that
are trying to reheat chips and things
like that and the problem we talked
earlier you know today about you know
sort of different types of solder and
things like that and you know if you
were to actually heat up a BGA chip that
had not suffered drop damage so it
doesn't have a crack in the lead-free
joint but if you heat it up to a
temperature that's like far below what
lead-free solder will flow out so let's
say you heat it up to like you know 100
and 180 degrees but not to 17 see this
is Celsius so this is like you know far
far you know your of your home oven and
your and your hairdryer can't possibly
heat up to like lead-free solder flow
temperatures so if you were to heat up
that chip it does tend to work you know
and that's sort of like you know what's
up with that because we think that we're
like yes you know it's kind of like
you're just sort of heating up the chip
itself has some of the eutectic solder
the leaded solder inside it yeah you
think you can read inside yeah so you
can kind of like make the chick chip
itself better you know but it's not
really a lasting durable repair
absolutely well that's what we're seeing
happen but there's no way you can get
new ICS for those machines right so
that's that's tough yeah exactly you
know so the right repair for that is to
replace the ice is to replace that BGA
chip can't find it that's and that's in
the case I mean that's why a lot of
these board level repairs make sense
because you have a board for an iPhone
you can't go out there and buy new
boards right for these things right and
and even if you could start with a bare
board you can't get all the components
with the right firmware on them so you
have to do
vesicle repair right so and just sort of
you know knowing your history makes a
lot of sense if I have this phone here
let's say this phone had a u2 chip
failure because of the charging using a
non Apple charger and it kind of had
some sort of over voltage situation well
that means that the touch IC chip is
fine
it was never dropped yeah it's no reason
that there would be anything wrong with
it so I could harvest a touch IC chip
and put it in some other phone that was
drunk you know so it so it does make
sense you know if you kind of really
think is it a chip failure or is it a
failure of the balls you know like what
what's going on and you know and and and
really think rather than just like rely
on the internet because the Internet is
the Internet wise you know it is it is
you know just full of misinformation and
misguided stuff you know well that's why
I fix it everything is a button and
everything up and downs that's right
that's right and it and it is the repair
community's responsibility I don't
expect for every but I don't think that
that you know we have a responsibility
to know everything on day one you know
but the repair community as we know
better do better and that means it's
your responsibility right your
responsibility to edit right and and and
vote and learn and I mean the nice thing
about something like this phone so
incredibly complex ball and huge amount
of engineering there's a relatively few
number of common failures do you don't
have to learn how everything works right
you can just learn about the half
they're so very common failures on an
iPhone 5 oh right you can easily be
successful you know by just sort of
saying I'm gonna address these sort of
patterns of failure because there's so
many iPhones you can make a successful
business just you know learning some
technical proficiency to be able to kind
of address the common stuff you know
when this you know like on this on this
mini retina when that power chip fails
which it does you know this thing kind
of can get a drop so here's a question
if this thing was dropped what's the
right repair replacing the chip
rebelling the chip reflowing the chip
what would you say I would probably say
reflowing the chip and I'm yes yes
because a draft right drop
means it's probably a cool joint there
you know some one of the balls just is
not making connection so if I could
reflow solder make a good connection the
chip itself is fine right okay what's
the right repair if the if this is you
know coming in and saying I left it on
my car - and it's got you know like a
temperature warning and now it doesn't
work at all so maybe that's a bad IC
yeah exactly because the heat damaged it
internally it's not gonna be you know
yes so fantastic but you know absolutely
right you know so so what we're saying
here though as you can see this sort of
under fill' under film makes sense
because you do drop phones a lot and so
you know it does make sense from a
design perspective to you know to sort
of problem-solve and say well how can we
get better contact and less damage from
drops and the Apple designers were not
actually trying to make repair a giant
pain for everyone they were trying to
say you know hey let's make a better
choice we see this lot and it's a repair
ability versus durability treat right
and in this case maybe it's it's correct
to err on the side of durable right so
it certainly makes yes it does and
sometimes just not feasible you know so
I wouldn't want to kind of create the
impression that like you can replace any
chip it's not feasible to replace
certain chips that are just like in a
area of really high chip density like
this one where you're gonna have under
fill was was a liquid that was squirted
under that chip to flow around and
encapsulate every ball and then cured to
be rock hard right you know that's gonna
be a nightmare when you actually try to
replace the chip