hey everybody how's it going today we
are going to fix a macbook
so here
we're going to plug it in
see how many amps it's taking
and what do you know
0.012
let's see
what this is for
let's see where we are so let's see what
what the purpose what's going on here so
can you
can you tell me
what you see
because i see water on smc reset and
pp3v42
pp3v42 is what is necessary to get a
green light
an smc reset is required for the smc to
turn on so that it charges
the macbook
so
i think this one might actually be an
easy one
okay
the ssd connector has food on it
or bug one or the other
either way i'm gonna be washing my hands
before i touch anything else when i'm
done with this computer
because this is gross
huh hi hi is here i see he's trying to
distract himself from the homework that
he's supposed to be doing
hi hi
he is distracting himself from homework
that he's looking that he's probably
supposed to be doing
i would get a board heater lemon lust
don't use chip quick don't okay wait are
you don't use
chip quick uh you're using you're using
firstly you're supposed to use chip
quick to remove
try help you in removing the old solder
you're not actually supposed to use chip
quick to solder the new but i tend to
not like chip quick in general for that
type of stuff i would just get a board
heater you're going to need it
eventually or what you could do if you
don't have the ability to have a board
here put your board in an oven and heat
it to
about i would say
like a hundred celsius just 100 celsius
not enough to melt solder not even close
but enough that the board itself is
preheated and all the the you know the
tough layers in the board are going to
already be preheated and then get to
work if you don't want to buy a
preheater and that's if you don't want
to buy a preheater or waste money on it
in the beginning that's what i would do
i would uh get the
what i would do
i forgot what i was saying in the middle
of the sentence
okay i don't remember what i was talking
about but i'm sure it'll come back to me
later
uh
where was i
do i see someone's nail probably i
wouldn't be surprised if you had nails
in here
it's there's no problem with putting a
board in an oven if you're not putting
the board in the oven for the purposes
of reflowing or soldering something
at least when we're talking about this i
mean you could literally do this in a
kitchen oven you could just use you know
100 celsius or 212 freedom units and
just have the board heated up just
enough that when you get to do your
normal soldering on it yet it's a little
bit easier to everything just kind of
comes off a little easier
and the benefit to that is that you're
not going to be using as much heat as
you otherwise would be using
if
you were
if the board was not already heated on
the so on each individual chip so for
instance let the board is going to be
absorbing the heat as i'm heating the
chip right so if the chip itself is
really really cold and the board is cold
even if i'm putting 500 celsius on top
of this chip i'm burning the chip
but all of the heat is being absorbed by
the board at the solder joint so i'm not
going to actually melt the solder joints
i am still destroying the top of the
chip i'm killing this chip by doing that
so you want to have the board kind of at
a temperature that allows you to use the
lowest possible temperature you need to
desolder the chip itself or to work on
the component that you're working on
which is why i don't immediately hotter
the boards like this so one thing you
may notice a lot of the time is i'll
heat from here and then here and then
here that's kind of like localized
preheating of the board rather than just
doing this like i you almost never see
me do this the only time i do something
like this is when i'm looking to remove
something that when there's something
around it that i don't want to heat and
i know whatever it is that i'm eating
i'm throwing away
[Music]
okay we're going to take the drive out
we have all those little pokey solder
joints on the battery
that's fine
i'm a brave man
a brave brave brave brave man
okay
so everything's out of the machine
and uh
again my guess is this is just gonna be
a really basic one
just a really really
easy breezy super easy
just a little bit of adjustment
and maybe even reflowing without
on the on the j the j tag we're going to
remove
and we're just going to reflow this and
honestly i even think a reflow of that
may just do it i really think the
corrosion is just shorting everything
this looks like one of those cases where
actually just the reflow and a little
bit of filing might fix everything
might just a little bit of amtec flux
you know just the right amount of flux
right amount of flux
so the first thing we do is remove the
jtag connector
nothing good comes from jtag connectors
this allows somebody at the apple
facility to plug in the device to get an
idea of what's going on with it or to
program the bios
i don't know i don't get access to fun
stuff for the jtag connector so why
should they
but seriously this is a liability
because what that little connector does
over there is it's a point that can be
corroded it kind of amplifies the
potential chances of getting corroded
because you got all the
copper and everything in the connector
and it winds up shorting things together
that don't need to be shorted together
so i prefer to get rid of it i don't
really care if these if these pads are
good because they're not going anything
anymore i just care there's nothing no
potential for shorting between them i
don't want bios pins or pads getting
short at the grounds i don't want pp3p42
or smc reset or anything else that could
be construed as important to getting
shorted as a result of this jtag
existing so
i'm just going to get rid of the solder
on all of those also one thing to make
sure of while you're doing this is that
you do not remove the solder from the
spi rom resistors that are right above
it that will be bad for you
bad for
that
now
i do not use jtacs
i do not like jtags
so
you can't wick with a micro pencil
that's just freaking ridiculous
i don't know why i actually expected
that to work
okay so
two things that need to be done here
a reflowing of the pp3 before two
underscore g3 hot area to ensure that
there's no corrosion shorting things
like this over here see that i'm gonna
have to turn up the hdr a little bit for
you to see that
okay there you go see this over here
admittedly that probably doesn't need a
reflow it just needs you know
just moving
anyway yeah also you have board blood on
the bottom over there see that red stuff
that's board blood
i may go over that with a q-tip in a
moment and then we have the smc reset
chip over here
i believe this will actually turn on
again now if you look on the bottom left
corner you'll see that those two pins in
the bottom left corner are shorted
together by all that little powder all
that little dust all the little stuff
and first thing i want to do
is i want those solder joints to
actually become like proper ones again
and i also want the flux and the heat to
clean away all that junk now i don't
trust that that's going to do it on that
section because that's considerably
nastier than the other two so i'm going
to add the proper amount of flux once
more
and i'm actually going to go over it
like this now this is one area where i i
respect joanna stern at the wall street
journal lovely amazing reporter however
she said that this is not like filing
your nails and as you can see it is
actually just like filing your nails
right here i always file my nails using
a t30 kn soldering iron at 750
fahrenheit please don't do that at home
i'm kidding and so we're going to what
this does is i am going to be
you know kind of filling in any void in
the old solder
going to be getting rid of any junk if
there's any dirt over there it's going
to get burned away in this giant ball of
soldering flux i also got rid of that
capacitor over there by accident but no
big deal we'll just get another one
no big deal and as you can see that the
bottom
left
two pads look beautiful whereas before
they looked horrible
and it's just it's a night and day
difference over there compared to what
you had before
turn down the hdr a little bit
can't get to can't get drunk on hdr like
that
it's a real night and day difference
over there
i don't believe that capacitor is
essential i think that's as essential as
andrew cuomo's career on this
motherboard i think it may just be a cap
to ground for some basic thing but you
know i still want to put it there make
things nice it's there for a reason i
might as well put it back i'm gonna get
myself a donor board it looks like all
the donors in this office have been
stolen since i haven't been here for
quite a while which is understandable
you know if i don't show up for a few
weeks makes sense that
the stuff that's in there get used for
people out here that are doing actual
work
not mad at all at that
the only thing that i'm mad at is that
haihai is watching the stream while
procrastinating doing his homework
college is what's going to ensure that
high high has better opportunities than
working at a repair shop like this or
running a repair shop like this when he
gets to be my age
and he better pay attention in those
classes
lest he wind up like me
okay so
just gonna put that there and i i bet
you
everything this is gonna work perfectly
fine
i see you hi hi i can actually see you
i see you avoiding your homework
i know you're avoiding your homework
now watch surface tension put that cap
into place
that cap is literally exactly where it
was when it was soldered on the board by
some machine
in shenzhen or taipei or south korea or
whatever the hell this thing gets done
i mean
that is beautiful that is gorgeous and
you're going to see a fan spin and this
is why the a1466 air is so beautiful
because it always fails in these really
really predictable no easy ways to fix
they're very very very friendly to
repair compared to a lot of other
devices
i give it a little bit of time to cool
off just a little a little bit just a
little bit
the board had some time to cool off when
i went over there but this area that i
heated only had a minimal time to cool
off since i just heated it again and i
think we should be good to go now you're
going to see this light turn green and
this is going to turn on
it's going to be like a symphony
see that this is a symphony the light is
orange and everything turned on so let's
go over why that would cause us to not
have a green light for the millionth
time
i will go over that for the millionth
time for all of you for those of you who
don't understand this so i need to go
over this on an older board because i
can't get you a schematic for the dcn
board on this
so that's what i'm going to do i'm going
to find an older board that makes it
easy for me to show you the schematic
and the board view
and
you'll learn something from it
i guarantee you'll learn something from
it if you want to pay attention
it's up to you if you pay attention
though
do you always need flux always
always
you always need copious amounts of flux
lots of flux i love flux i put flux on
everything
flux on my pizza okay no i'm not
isn't
i don't put flux on your food that's
actually really bad
okay so
why are you trying to be my dad john
it's weird
uh so
okay so
[Music]
where is you sick
come on
come on you little chip
come on your little one wire circuit
where are you
here one wire
here one wire one wire one wire one wire
one wire where are you one wire
i can't believe i forgot where the one
wire is ah
here we go
so
for the light to turn green in the
charger it needs to actually talk to the
computer
that's really important here
so let's just get this all on the screen
so you can see it really nicely
okay i think that's a large enough that
you can see it properly so this is the
power jack right
now this has three things 18 volts
ground
to complete the circuit and adapter
sense which is misspelled because well
apple so adapter sends is going to be
where the adapter
adapter not adopt or
speaks
with
the
smc
so this is going to go to this chip over
here now what does this thing do it's
kind of like a bodyguard so it's very
easy to plug this charger in wrong
because it's magnetic it's not like a
barrel jack so you could accidentally if
somebody's drunk they could be doing
something like
i want
jack
and you know it can end very poorly
because if that happens if you have
somebody who's an idiot and drunk doing
that and let's face it we've all been
drunk and idiots at times in our lives
most likely you could have 18 volts go
to ground you could have the 18 volts go
to the adapter sense line and again
adapter sense is going to speak to the
smc so when we go to sys1 wire over here
sys1 wire is going to go straight to a
little chip called a system management
controller
and it's going to talk to the charge to
get the charge to turn on see this sys1
wire
u4900
smc
now
if instead of a little two or three volt
data line talking to the smc and saying
hi i'm a macbook charger are you a real
macbook charger yes i am a real macbook
charger turn on
instead if instead of having a
conversation it talking what happens is
it just sends 18 volts what do you think
is going to happen this little smc this
little smc that was expecting a little
two or three volt data line it's gonna
get it's gonna get fried and the
way we keep it from getting fried is by
having this little bodyguard chip over
here u6900 now this little bodyguard
chip over here it needs to actually turn
on needs to get voltage turn on so that
it can actually do its job and let
anything through so what this does is
this is going to get powered by this
what is this this is a logic gate this
is going to say is is if smc bc ac okay
is present then send 3.42 volts out so
you need this power l pp3 or 442
underscore g3 hot you need the power to
be present that power rail's not present
then this entire circuit's not going to
work and you won't get a green light in
the chip that creates pp3
score g3 hot where's this corroded chip
right over here that also shows up on
this jtag connector over here now for
the smc because that's the second part
of this equation when you take a look at
the schematic the system management
controller is also of crucial importance
here because it's going to it's the
thing that actually does the talking now
the smc needs to turn on and what's
going to control it turning on
the smc reset chip the smc reset chip is
going to in turn control this actually
turning on so let's find the smc reset
chip right here
all right smc reset chip is here
so the way this works is you have a
little pull up resistor that ensures
that smc reset l is always up remember
reset is kind of like holding down the
reset button on your desktop computer if
you hold it down the computer's on but
it's not actually doing anything it's
stuck in this purgatory before it's not
posted yet but the hardware is on and
once you take your finger off the reset
button then the reset button will be low
so this is in reset mode when it's high
and it is not in reset mode when it is
low
wait i got that wrong ah edit edit you
underscore l means that it is in reset
mode when it is low so when the signal
is 0 volts or 0.5 volts it's like
hitting your reset button when it's high
it's not being reset we don't want now
the way that this needs to work is
this
smc chip over here it's going to cr what
is that gross anyway i got to clean that
the smc chip it needs
3.42 volts to be stable like perfectly
flat before it actually tries to turn on
if it tries to turn on with sm with pp3
before to it 5 volts or 2 volts or 1
volt it's not going to work so what smc
reset l is it's kind of like a brownout
detector it's going to
delay
the smc from turning on for about a
quarter of a second or so that's by the
way why it takes about a second for your
green light to actually turn green if
you have a charger that's not a knock
off in a macbook if you have a charger
that actually doesn't want to speak to
the smc before it turns on which is
charges that are not knock-offs you'll
notice that there's that little delay
and that little delay is the delay of
waiting for pp3v42 to stabilize to
perfectly clean three volts because
that's what powers the smc
before the smc actually turns on and sm
this little chip over here ensures that
that happens so that chip is the smc
reset chip over here and it has
it ha it has an input over here pp3 3v3
s5 smc and all these other things it's
actually i believe this is actually a
sub rail of ppe 3v42 not pp3 s5 but
that's for another video but this chip
is going to wait about a quarter of a
second for everything to stabilize in
the machine before it allows the smc to
actually turn on and it's very necessary
now if this chip is corroded maybe it's
going to keep the smc in reset mode
permanently maybe it's going to keep
this smc reset l signal held down low
meaning that the smc stays in reset mode
and never actually works similarly if
you keep your power button i mean your
reset button on your computer held in
and it never actually works so the third
thing that we have to look at here is if
you take a look at
flex board view where are you flex where
are you flex come back you little
okay there we are is the
what we have to look at is
the jtag connector so the jtag connector
is this horrible little thing over here
there we go
and it's corroded as you can see the
corrosion was on the pad all the way to
the bottom left and that's pp342 so i
imagine that the corrosion over there
had pp342 going to ground it's very
possible that this rail was short at the
ground or it's possible that the
corrosion and smc reset was holding smc
reset down no way to really know for
sure which one it is after the fact
because we already did the work because
i just didn't feel like going through
the whole thing when i knew exactly what
was wrong with the board already that
being said
that that is it that really is it now we
do have some cleaning work to do other
areas of the board this board is still
disgusting it has not been treated very
well and we are going to put the proper
amount of flux on these areas and give
them just a little bit of reflow and a
little bit of love because we can't let
this go back to the customer like that
this is also going to go through an
ultrasonic cleaner which will pick up
anything that i just so happen to miss
but i always prefer to have the joints
be
reflowed and put back into place
properly rather than just cleaning
everything off because i want there to
be an actual solder joint that's
respectable on these areas of the board
again and also let's say you have a
capacitor that looks like this i don't
want to reuse a capacitor that looks
like that without at least filing it on
the side we're going to file it and
we're going to make it look nice again
so just a little bit of
a little bit of this
no big deal
again we have here is the proper amount
of flux
okay
so
now that little crater over there
there's not really much i can do about
that
what i can do is on a cap that looks
like that a little bit of foiling and it
looks beautiful and shiny again
like this resistor we just give it a
little bit of filing i don't want to
only file the top no way in hell i want
the bottom of it to be beautiful
okay
and you look around you look around
you've got this over here that was
corroded
so
one's a little too corroded for my
liking
no big deal we just remove it
i want to get rid of the old solder
that's why i'm using an obnoxious ball
over here
and also i want to suck up any of that
nasty stuff that's there onto the iron
now as you can see this on the left pad
it doesn't look like a nice neat even
blob it actually looks like the
corrosion is not allowing solder to
stick on the top of it as i've said you
don't want to solder on top of corrosion
now
solder wick can often work like
sandpaper in a really beautiful way and
over here remember what we want to do is
kind of sand it down
so that i can also remove the junky
solder
that's there so the wick is going to
serve double purpose over there
so
i have some nice gootwick over here
and just a little bit of happy scraping
see scrape
now i can do a little bit of happy
scraping like this and i got my pad back
see i got most of my pad back there
you don't want to do too much because
you see how around the pad like around
the pad you can see how some of the
some of the the coating has kind of come
off
now if you're a real pro sometimes you
can manage to not scrape any of that
coating off around it
while you're doing that
either way see that is going to be
considerably better than me just
soldering a cap on top of corrosion you
don't want to solder on top of corrosion
and let's get this as well since this
area got a little
hit
look at how pretty that all is
look at how pretty it is
just keep going until it's a happy
little macbook again grant now see
this is also why you take the board out
because all the work that i did that get
the thing to turn on was done on the
other side of the board
and it turned on did it not i mean
there are there are people out there in
this world that would not even take the
board out they would just fix what they
see on the top and give it back
why take screws out when you don't have
to
but at the end of the day that's not a
real job
it's not a real repair
you want to do a real repair
don't stand up
you absolute bastard
i'll catch you and bring you back
you don't get to jump out the factory
there will be a net and a trampoline to
bounce you back into the factory to go
back into another macbook
yes just like that
nice try mofo nice try
if their employees can't get away then
you surely can't get away either
all right
so
just like filing your nails
these two are not good enough
these two have too much corrosion under
them
i'm not just gonna file those those
gotta go
yeah you can't be that damaged and still
be here
same with this cap over here this end is
completely gone on this capacitor all
the way to the right
it's not rehabilitable
to
in my opinion
that's fine
that section of the board is a main
power rail so it has a high thermal mass
it's very difficult to actually get
anything off of there nicely with a
micro pencil
also we're gonna have to be a little
creative with the wicking
to try and scrape a pad away
because that this doesn't look like
there's any pad under there
you may have to knife it actually they
have to do some knifing and scraping
to get that back
yeah it looks like some knifing and
scraping is going to be required there
no worries
so
okay on the left side we got ourselves a
something that i could solder to that's
a win
on the right side it looks like we just
got junk though
yeah there's not really left there
so this is the part where we're gonna
figure out what that is
so we can figure out a place that we can
grab it from
no big deal stuff like that happens you
know not a big deal
nothing to get nothing to get scared of
so on the left you have smc tms that
goes straight to the smc so thank god
that pad is there on the right you got
pp342 so i could just put the resistor
facing upwards and then run a wire from
here to there
or just have the resistor literally go
from here to here i got options i don't
have to solder directly to here
this has to has to go there but this i
mean this this i can get that from
anywhere so that's not a big deal to me
at all
there's no no fear no fear
no fear at all
this cap over here is also not essential
you already have another like another
several pp342 bypass caps over there
but i'll scrape off a space for it
anyway
and that pad is was completely corroded
out under there so where it is
[Laughter]
so
i've never seen a fear this sticker ever
in my life zombie
so
that's going to require a micro jumper
to be
actually it may not let's see
yeah that's soldered on there no micro
jumper needed
a micro jumper on a like this small
bypass cap seems like overkill
that's just
that's ocd
[Music]
so
[Laughter]
so
[Laughter]
gotta get flowed into place with some
hot air in a moment
[Laughter]
now for the smc resistor
so
i'm actually gonna use that pro point
as an anchor
so
[Laughter]
make sure my iron always is a little bit
on the tip
you always want to be prepared with a
little bit on the tip
you never know when you'll need to use
it
just a little bit on the tip
so
i can't grab the wire
i actually couldn't grab it for
[Laughter]
okay so that resistor is not where it's
supposed to be but it is soldered to
what it's supposed to be soldered to and
at the end of the day
that's what matters
so that's all cleaned up
and
much better
i'm not dealing with corroded
anymore
again would have worked
yeah but you know that this customer
would have been back in like
eight months or a year saying it doesn't
work after you fixed it and that's not
what you want you want things to work
for a nice long time when you fix them
you want to know that you got everything
it's a nice little work of art
you know now the final piece is flowing
everything into place nicely
yeah
i think that there may be a little bit
of a void
on the bottom solder joint of that
resistor because i just kind of hot
aired it onto a pro point that i
semi-tinned
so i'm just gonna
touch that up a little bit
that's a little bit of a fat boy there
[Laughter]
can i hold this resistor down while i
solder who am i kidding i can barely
control my hands anymore
why am i even doing this
ah here we go
okay i got it long enough
see there's no more solder void
and then we do this flow it into exactly
where it wants to be
and there we go all right
that's beautiful
so that's it for today and as always i
hope that you learned something i'll see
you all in the next video
bye now