all right so today I'm going to be going
over a basic no backlight issue on a
board that was dropped off here so one
of the things you may notice is I have a
new microphone here uh one of the people
on the channel Zao DK was actually kind
enough to send me a DPA 4066 microphone
for dirt cheap it didn't have an XLR
connector and the wireframe is all
[ __ ] up but when you see what I paid
for this microphone and what this
microphone cost new like this is worth
it and um the thing is you may think
that it doesn't sound much different but
when like the amount of work that you
have to do to get this [ __ ] piece of
[ __ ] sh microphone this um wh20 w35
something like that what you have to do
to get this sm35 or whatever from short
to sound like this is ridiculous it's
like a good 5 or 10 minutes just
completely wasted in
settings so that I don't sound like I'm
uh you know
Underwater All right so let's start
here so the first thing I'm going to do
on this no backl board is measure very
short to ground on my
multimeter trying to rearrange the desk
so that you can see stuff better that's
not working out the way I
want okay so when I check for a short to
ground on backlight output I get 0.014
voltage drop which totally means short
to ground now honestly the amount of
time it's going to take for me to run
power through it is actually less time
than it would take for me to Simply
remove the very few components that
usually go bad in the backlight circuit
which is the LED driver the LCD
connector or the output caps in that
particular order now here I'm going to
guess that it's not the LCD connector
because this was in water this was
do-it-yourself screen replacement so
what I'm going to start is I'm going to
start by removing the LED driver so
let's see if you can see that in the
screen that is very very blue we're
going to adjust that in a second so it's
not blue so you can actually see [ __ ]
okay focus focus
mofo okay get rid of that
blue come
on here we go we're almost
there oh I have so little patience for
this little click wheel on this camera
Tada perfect okay turn the air filter on
because I don't want to inhale [ __ ] that
[ __ ] you
up I'm satisfied that that's ready to be
removed
now let's see if my short is gone again
the reason I the other reason I don't
like running power through to find the
short here is because when the short is
inside the LCD connector and you run
power through to see if that gets rid of
it bad things happen and it seems like
it's probably in the LCD connector so
let's remove that next again if you run
power through to find the short it's in
the LCD connector you burn a hole in the
board so probably yeah it wasn't the LED
driver well I mean it could have been it
could have been the LED driver and
something else but but most likely it is
something
else that's fine because that chip is
$161 and takes very little time to put
back on this is the thing like I don't
even get easy no backlight jobs anymore
I can't remember the last time I charged
a few I can't remember the last time I
replace the fuse I can't remember the
last time I had a no power issue that
was fixable by replacing the TPS 5125
like I I
can't huh so let's see if it went
away hopefully it went away go back to
the multimeter
view okay what do I
get and still shorted oh
boy this is going to so this means that
okay you remember what I said how I
don't run power through to find the
short because if it's in the LCD
connector on the backlight rail bad
things happen well the reason that it's
doing this now is because I want to do a
video and as I say when I want to do a
video the Stars aligned to make me look
like an idiot which is just lovely all
right so what I'm doing right now is I'm
just removing all the old crudded lead
free solder from the LCD
connector and from the LED driver since
I'm going to have to put that [ __ ] back
on okay let's continue in our Quest so
it can be output capacitors we're let's
just knock those off
it's probably not going to be those it's
going to be the last thing I
remove and let's go to Output capacitor
in a
second still shorted so now I remove the
larger output capacitors and if that
doesn't fix it then I will start running
power of course it's not going to be
what it is 99% of the [ __ ] time
because I'm doing a video
[ __ ] never ceases to amaze
me so I'm removing oh probably put it so
you can see so yeah that's I don't need
a microscope to remove stuff that's this
big though so those are the two output
caps on the backlight
circuit this is
it and let's
see yeah you see that that that means
this is probably my problem which again
99.999% of the [ __ ] time it's not
this because I'm doing in a video uh
it's it's it's going to be this I got to
fix the wireframe in this mic so that it
stays by my mouth so then the Short's
going to be gone probably which means I
got to put all that [ __ ] back on that I
took off doesn't
it of course it's gone of course it's
the thing that it never is because I'm
doing a
mother oh piece of [ __ ] all
right okay let's get go to putting ion
everything that I took
off now the right thing to do the
absolute positively right thing to do is
to flatten the pads to not keep them
tinned so that everything is the right
size I'm going to do since I took
everything off and I want to save time
and I know damn well how to solder a
chip with only 25 balls that's this
small I'm just going to put this on top
of that yep I'm evil I
know I know I know troll your heart out
I suck at my crap blah blah
blah all
right there are some chips where if it's
tined it really does screw it up and
this is this is not one of them and I
know that from experience so I'm just
kind of doing what I
want see it's dancing one 2 3 3 seconds
of dancing and I'm happy okay now let's
put the LCD connector back on that I
decided to rip off because I'm an
idiot okay LCD connector let's move this
ins so I get some
space let's move the old solder from
there can't believe I removed all that
[ __ ] when it
was you got to realize that it is never
never the output capacitor like
99.999999% of the [ __ ] time it's not
that it's just that because of this
video and you would have been able to
tell that with the short test
immediately with the you know putting
power on
there see it's when I don't decide to
use the power supply to find the short
that the short is going to be somewhere
where it would have been safe and it's
when I do decide to use the power supply
to find the short that I'm going to burn
a hole in the [ __ ]
motherboard oh man can't make this [ __ ]
up
let's find a board I can steal that
stuff from I actually have a 3115 here
that I'm using as a donor board for the
SMC and I've got yeah has has caps on it
beautiful wait wait a second the cap is
worse than you see
this oh hell no
next whoa that is not going back
on okay
next those look even worse next
stolen
dude I there is so much [ __ ] that has
been stolen from all of the boards that
are in my pile of donors so much that
has been stolen that if you actually
threw this away and you did not throw it
into an eways container I don't even
think you get in trouble for IL legally
disposing of ew
like my boards don't even qualify as
E-Waste anymore
it's they're just
waste I mean
this
okay good get on there
next
get on there okay LCD connector this is
the real fun because I don't have my
flux syringe anymore I really do have to
get another one of
those okay oh and I also accidentally
got the LCD connectors that don't have
those little hooks so I got to align it
manually so you see how there's holes by
the LCD connector like the upper left
corner over here and here so for the
newer boards they have these LCD
connectors that I love that have those
there so that you don't have to do any
work in aligning it it just kind of
aligns itself for you which is you know
and I'm always for somebody else doing
the work like there's I don't see that
to be any reason for you to do work when
something else will do it for
you so we're going to just clean this
up make it nice and
clean my ESD SA sparkle paper towel from
Amazon we'll make sure that that is nice
and clean my ESD safe paper
towel oh man I should tell you what I
think about
ESD
okay okay until I get my until I get a
new syringe for my flux I lost my others
at the classes I'm using my tweezers
which is awful this is a terrible way to
apply flux please do not follow my awful
example oh yeah this is this is not the
way to do
it you got to um you you have to be
feeling sick at the way that I'm
applying flux right now I really do need
to remember to order
that and look I let a little wire onto
the board
I don't really care if I make a mess
right now because the all these boards
like that I do this kind of work on I
just I dumped them into the cleaner
anyway when they're completed so it can
look like total [ __ ] right now I don't
care because the customer is never going
to see
that like I mean when people say there's
excess flux I
mean you know they do make things that
will clean that off believe it or
not so again you want to push down on
the connector as hard as you can without
destroying the board the whole idea here
is to make the P the pins of the LCD
connector stay really flat onto the
board so that when you solder it's kind
of I mean in an ideal world it would
work like this in an Ideal World you've
pushed your connector onto the board so
hard that without even soldering your
joints it would work that's what you're
looking for you want that type of
connection where you don't even have to
solder and your joints work just
fine that would be ideal so like that
connector is pushing on the board you
turn it on you use it and everything is
good and beautiful but you know the
solder is really just completing what's
already there it's not what is being
used to make the connection that's the
way I see it anyway so now we're going
to change over to my curvy
tip love the curvy
tip
and we'll get
started that's this is way too big
solder for this
application but it's
working okay we're gonna
go by each pin let's get the right
solder for this application which is
something that's much
smaller even mind we didn't actually
have to take this off I just I I put a
little bit of extra safety when I'm do
working with the backlight circuit
because I know how easy it is to destroy
this and here's the thing you may say
okay well don't need to use 12 volts or
40 volts or whatever because it's just
it's the backlight circuit you can start
with one Volt or two volt and then see
what's getting hot that's the thing
you're not going to feel the connector
getting hot the connector is a big hunk
of metal it's not a
component right you know you're not
going to
know that it's that until you see a
little hole in your
board I love amtech flux look at
that doesn't even need a second
application well just as I said that it
kind of needs a second application
but notice that most of the time I'm not
using the tip of the iron I'm using the
elbow of it cuz the tip of the of these
really fine irons it doesn't it get
hotter you don't have the solder uh move
to it the same that it moves to the
Elbow because there's more heat at the
elbow so understanding how your tip work
is an important
thing
yoink H I just made a mess and I fixed
it
okay there's one LED return pin over
there that I don't I did an awful job
on okay
Flo
Flo clean the fluxo so that I can see it
and do my my joint
test this hot air is not at a
temperature that where it can melt
solder it's just at a temperature it'll
make the flux easier to move away with
my ESD
safe sparkle paper
towel why don't you get a brush the
brush don't clean the same way
mofo you should get this special brush I
don't want the brush [ __ ]
you so many trolling comments with
that why do you care why does it bother
you so much when you see me use
something okay so the sparkle paper
towel has a little bit of the fibers
that the usual paper towels that I use
don't okay point taken point taken you
[ __ ] YouTube
troll point taken that's all going to
come off with toothbrush alcohol in the
cleaner the Ultrasonic Cleaner makes all
that
humble okay joint is
good I'm coming up on a joint that I
don't really
trust I'll go over that one again even
though it passed my little test
here okay and out and all that's left is
fuse and output
caps let's get that fuse
[Music]
off say goodbye
fuse
okay new fuse
on come on stop sticking in my
tweezer
that gets rid of that stupid myth that
you need a hot air station to do a fuse
so for all you people when I say replace
the fuse do not jump it with a wire I
can't because I don't have the tool
YouTu yeah if you want to make it like
sit perfect okay hot air you know you
don't even need hot air for that you
just need flux and a proper method of
applying it with the regular iron but
really you can totally do that with the
regular iron I just did it I just showed
you okay now for this nasty
pile now to fix what the actual [ __ ]
problem was the entire
time let's get rid of the lead free
solder that was on the
pad it's all going to get sucked up into
that ball that's on the elbow and then
we whisk
away I should be using the flat tip for
this
but it's not that
critical look
away okay now
turn the pads and get ready for my new
capacitor heat the pad then Rush the
solder heat the pad then Rush the solder
in heat the pad then Rush the solder in
you don't want to do this thing where
you know you're you're you're
putting like you put soldo on the tip of
your iron and then you touch it there
because then it won't the flux won't act
will activate prematurely and then
you'll have no flux left on the inside
the solder and then then it won't flow
and you'll get a shitty joint okay now
for a board that I can steal those two
from here we go the board that I'm
stealing the SMC from oh I've already
stolen the Caps from that
one how about this one
huh
terrible slightly less
terrible you can't even see that here
now you contr
the main idea is to get it as clo is to
get it pushed on the board cuz you can
always fix the what the looks like on
the side later but it has to be flat on
the board because if it's not then you
get leverage where it can easily fall
off and if it's if it's tapped if it's
flat on the board it's going to be
really hard to knock that thing
off and by the way this is not the way
to apply flux don't follow this [ __ ]
example you use a proper syringe with a
proper tip this is this
[ __ ] but it works until I remember
to buy the syringes
a lot of things that you have to
remember to do if you're me so the
things that are really not crazy
important kind of get tossed to the
Wayside okay I'm ready to show that this
has a
backlight also ready to clean my
desk one of the most important things in
this business is to have a desk the desk
that's not a mess cuz once you let your
desk become a mess this is what you're
looking at all day and your brain starts
to mimic what's in front of you so if
your desk is a mess then your brain
becomes a mess and we we make money
ultimately using our brain you know
somebody I I said one time that I suck
at soldering and then uh somebody said
no you don't you make a living at it and
then Sunny who was with me who is
allowed to make these jokes said
something like no if Lewis made a living
off of his soldering he would be
bankrupt Lewis makes a living off of his
brain which is correct you know you you
make a living off of your brain so your
desk cannot be a mess if your desk is a
mess then your life becomes a mess and
that's that's no good so as I'm working
I always try to clean my desk up if I
notice that it's starting to become a
mess I will start to clean it so that it
is not a mess because again I need my
brain to be in tiptop shape and I can't
let like just can't let everything go to
[ __ ] in front of
me so we're going to get a ram
stick I got my test Ram stick in
here DC in
board and if this works I'm going to
throw it in the ultrasonic brush off the
junk okay let's plug this in and hope to
not have
fire there's no reason for those caps to
go by the way they just go
and you know when they feel like it's
not like water doesn't do that plugging
your screen in upside down doesn't do
that it just means that you're really
unlucky
okay you can see I have a light which
means I'm set I should probably actually
show you what went on in the circuit so
usually it's either the LCD connector
which is up here C ppv out s SW
backlight it can be this capacitor which
it it never ever
is it could
be the LED driver chip over
here it could be one of these outpa
capacitors which again it never is
except for now that or it could be
inside the board so this time it was one
of these two outpa capacitors I didn't
bother checking which I just replaced
them both because it's easy and they
cost virtually nothing and that was it
when I was done I had a working board so
again no backlight now I have backlight
now customer is Happy Well I can't say
that customer is happy but customer has
a working computer and that's really all
I give a [ __ ] about and I'm set hope you
learn something