Master Laptop Motherboard Voltages and Signals Tracking | Charging Circuit Explained | Laptop repair

the AC okay exist in the pin

127 so we have 3 volt in the multimeter

so AC okay is good

19.1 volt this is the dcn let's check we

have 19 volt in the multimeter so we

have here PQ 52 these three pins are s

and this is to get let's check hi

everyone so welcome again to this video

where I'm going to teach you the charge

circuit from a to zed so please because

this is the first video where you see my

face I want more likes for this video

this video will be one of the top videos

in my channel so please guys why this

course is a very important course and is

one of the top course in my YouTube

channel because upon completion of this

curse you will be able to fix battery

not char charging issues battery not

detected battery works on adapter but

not on battery battery not recognized

laptop only powers on battery but not on

adapter laptop turns off when unplugged

battery drains too quickly adapter

connected not charging battery

percentage stuck laptop charging slowly

laptop charging but not increasing

percentage plugged in in not charging

issue inconsistent charging Behavior

laptop charging light blanking not

showing laptop doesn't recognize the

adapter and finally power adapter

overheating so please if you suffer from

any of these issues stay tuned this

video will help you a lot this is the

top samplified schematic that will help

you understand the Char circuit 100

person so this schematic is the same as

this here we going to see the

theoretical part here in the table where

I'm going to teach you how to follow

voltages and of course we going to see

all here in this motherboard using the

multimeter so please stay tuned let's

get started so first let's see an

overview about this schematic here we

have the DC jack as you see we have the

pgp1 so this is the DC jack in the

motherboard

pgp1 we have the

pl24 inductor the

pl24 inductor this one next to the DC

jack this is the input inductor and over

here we have two mosfets or switches

this is the first mosfit PQ 51 and the

second m moset PQ 52 so this mosfit is

PQ 51 and in the other side we will find

PQ 52 this is PQ 52 mosfet always next

to the D jar so basically this mosfit is

used for protection and this one we

called it a switch because it Le 19 volt

to pass from this side to this side we

have the current sens resistor PR

351 here we have the current sens

resistor PR

351 next to the battery connector the

purpose of the current sens resistor is

to calculate the current consumed by the

whole motherboard here we have the

charge IC pu 1 it's reference is I

6251 this is the charge IC we have pu 17

and for the reference as you can see we

have I

6251 we have the is iio this is the

circuit that is responsible for the

management of the whole power in the

motherboard this is the siio or the

super iio so here we have two voltage

Regulators that will generate the 12

volt to charge the battery battery then

here we have the mosfit or the switch

for the battery and also it's inductor

p45 but this channel will only work when

the adapter is removed so now let's see

how voltage travel into circuit step by

step from one point to other point first

of all we have the v in so VN equal to

19 volt the VN will pass through this

inductor and it will be present here in

the drain of this mosfit PQ 51 so let's

check PQ 51 so this is the mosfit as you

can see here we have PQ 51 okay this

reference PQ 56 is for this mosfit okay

here three pin mosfet but PQ 51 this is

it here we we have this do means this is

the SCE and over here we have the gate

and this is the drain we have to find 19

volt is in the drain so let's

check we have 19 volt in the multimeter

so we find 19 volt 19 volt is present

then 19 volt will goes in this direction

as you can see and in this direction

to power this IC we have here the DC in

so the DC end signal is about 19 volts

it is the working voltage for this IC so

without without the DC in the IC will

not work means we will not get 12 volt

we will not get anything in the circuit

so let's check the dcn in the pin 25

we have to find 19 volt so this is the

charge I see this dot here means this is

the p number one so 1 2 3 4 5 6 7 8 9 10

11 12 so here we have 12 and over here

we have 12 so the pin 24 is this one

because the rting is like this

counterclockwise okay one we have here

one this is the PIN number 12 here we

have 13 14 15 until 24 so this pin is

the PIN

24 so let's check this pin we have to

find 19 Vol in the multimeter this is

the dcn let's check we have 190 volt in

the multimeter so the

dcn is correct good so once we find 19

volt let's see the next step so here we

have the first step so this is the

second step the third step is the 90

voltage will goes in this direction as

you can see of course it will pass

through this resistor PR

359 and it will be applied to pin number

three in charge I so because we have

have these two resistors about 100 kilm

we will not get 19 volt here like the

dcn we will get a voltage usually

between 1.2 volt and 3.3 volt so let's

check into I so this is always the

charge IC let's locate the pin number

three so this is the PIN number three

here so 1 2 3 this pin number three is

connected to this resistor do you see

this part here this small part means we

have connection so let's check here in

this resistor we have 1.3 volts we find

1.3 volt so this step is good and the

third step also is good next Once the

charge I get these two signals this is

is basically two input signals we called

it also enable signals once it get this

signals here this one and this one it

will then generate the EC drive so this

is do step number four the AC Drive will

activate these two gates then the 19

voltage will pass in this direction but

let let's first check AC drive so for e

Drive it's about 8 volt so let's check

the Gate of this mosfit PQ 51 and this

mosfit PQ 52 so let's check the AC Drive

in the motherboard we have to find 8

volt in the gate of PQ 51 and PQ 52 so

let's check first the Gate of this

mosfet so here we have this Dot this is

the PIN number one 2 three and four so

the gate always is in the pin number

four so let's check pin number four we

have to find 8

volt as you can see in the milimeter we

have 8 volt so the AC drive here is good

let's now check the other mosfit PQ 52

so the second mosfit is in the other

side of the

motherboard so we have here PQ 52 so

this is the gate because here we have

this dot means these three pins are Serv

and this is to get let's

check also we have eight Vol so the AC

Drive is good in both mosfets so I will

prove to you why generating the AC

detect or the ACN we call it sometimes

AC sit or also enable we can call this

signal enable so this signal is very

important without this signal the EC

Drive will not be generated let's see

the proof please pay attention this

functional diagram is apart from the

charge IC do you see here the gate

signals these two signals in order to be

generated this IC should receive this

enable signal so this enable signal will

activate this IC and then this IC will

generate an output to activate this IC

and then this IC will generate the

control signals as you can see for the

gates so in our case the enable here is

the AC in about 1.3 volt so once we find

8 volt in these two gates means these

two mosfets are activated so a 19 volt

will pass here we will get here 19 volt

so this step also is good 19 volt also

will pass through this current sens

resistors and then we will get B+

19 volt let's check 19 volt in both

sides of this current sens resistor

p351 so we have the current sens

resistor

p351 let's check 19 volt in both sides

so here we have to find 19 volt this is

good let's check the other side we have

19 volt so once we find 19 volt in both

sides of this resistors why in both

sides because resistance is about 0 02

oh so the B+ is good so this step is

good we get the B+ from here the voltage

will be distributed to the whole Circuit

of the motherboard including the CPU

circuit the ram

circuit Etc so let's check if this B+ is

distributed to the the whole motherboard

or to the whole circuit in the

motherboard so now we got to check if

the 19 volt is distributed to all

circuit in the motherboard so let's

begin with this circuit here we have

this inductor we have to always locate

this inductor we have to find 19

volt we have 19 volt this is 3v 5 Vol

circuit here we have do not Bridge

circuit let's see if we have 19 Vol or

not we have 19 volt also here we have

the CPU circuit let's check this

inductor we have 19 volt let's go and

check do graphic card inductor we have

PL means this is inductor we have to

find 19 volt this is good let's go ahead

and check the ram circuit we have PL

indu here let's check we have 19 Vol why

I check 19 Vol in this kind of inductors

because those inductors are always in

every input for every circuit so the 90

volt is distributed to all circuits in

the motherboard good we find that the B+

is distributed to all circuit in the

motherboard means this STP also the St

number six is also good the distribution

of the main voltage is down 100% now the

19 volt will pass through this inductors

directly to source of this mosfit PQ 53

but it will stop here in the SE it will

not pass to other side because if it

pass to this side it will damage the

battery because the maximum voltage of

the battery is 12 volt why the voltage

will not pass to this side because this

mosfit contain inside it a protection

diode that will not let the voltage to

pass in the side so let's check this

mosfit we have to find 90 volt in h s

but the drain we should find Z volt so

let's check into motherboard so this is

PQ 53 as you can see here we have this

dot means this is s so we have to find

19 volt in the S as you can see in the

multimeter but in the drain we have to

find zero volt as you can see so here

it's a good mosfet the battery is

protected so the next step here is this

the 19 volt will travel in this

direction so we will get 19 volt hair in

the drain of PQ 62 so this is the step

number

seven let's check the drain of this

moset PQ 62 so we have here PQ 62 as you

can see so this is s you have to always

locate this point because the point

always refer to the pin number one so

three pin here for S this is the gate

and over here we have the drain so we

have to find 19 volt in the drain let's

check we have 19 volt in the multimeter

so the 19 volt is present means the the

last step about the main voltage is good

now let's move on to the next chapter so

once the Char I detect or receive the DC

in the AC in and also the B+ is here and

is distributed to all circuit in the

motherboard the charge circuit will

begin send the E key to this IC to the

super I about 3.3 volt so let's verify

the AC okay and the motherboard so this

is the siio as you can see near to the

charge I so the AC exist in the pin

127 as you can see in the schematic so

let's check the pin

127 so as you can see this Mark here

means this is the PIN number one over

here we have 32 the pin number 32 33

here we have 64 here 65 here we have 96

97 and over here we have 128 so the pin

127 should be this pin so we have three

volt in the multimeter so AC okay is

good so we find the AC okay means the

number eight is good the EC okay is good

so the E okay that the charge circuit

sent to the S iio is the same as power

good the charge I see here in form the

is iio because this is the boss here we

have

boss so this is the big boss in the Char

circuit always the charge IC refer to

its boss that's why this IC is the IC

that manage the whole power in the

motherboard so the charge IC will inform

this boss that the ACN is detected the

dcn is detected and also the main

voltage is distributed correctly so then

the siio will send another signal here

basically this

ISB data okay and also MB clock the same

as do but those signals will be sent to

the battery okay we going to discuss the

signals after so after receiving the AC

okay the isio will will send the acmb

data and acmb clock signal to this IC to

generate the uper gate here we have 10

okay here also we have 10 okay to

generate the upper gate to these two

mosfets we have PQ 62 and PQ 64 these

two mosfit will then generate the 12

volt to do battery here guys I have a

question why we all always speak about

12 volt not 19 Volt or 18 volt why so

let me explain to you and teach to how

to battery works in order to understand

why 12 volt and not 19 volt let's go

started so do you see here basically the

battery for the laptop composed of of

six CS okay we have these three CS are

connected in series okay and for each

still we have 3.7 Volt 2 amps 3.7 2 amps

3.7 to amps so when we connect the sees

in series means the the voltage will be

added will be increased but the current

will remain the same so means we have

3.7 here 3.7 3.7 so 3.7 + 3.7 + 3.7

equal

19.1

volt

means 12 volt okay we have another arow

here where we have three other CES okay

so this three other CES also is in

series means we have here 12 volt 2 amps

okay and here we have 12 Vol 2 amps

because those in series and those in

series now the two arrows is in parallel

means what when we have two blocks of

cells in parallel means what means the

current will be added means 2 Amp plus 2

Amp will be 4 amps okay we have here 4

amps but in parallel the voltage will

not be added will remain the same

voltage means we have here 12 volt 12

Vol it will be 12 Vol to within the

battery we have 12 volt for amps that's

why these two voltage Regulators

generate 12 volt not 19 volt not 18 volt

because the maximum voltage that the

battery can support is 12 volt based on

it configuration six seals with the

characteristics of 3.7 Volt 2 amps so

the next step guys this is a very

important step please pay attention the

next step is to generate

this signals this is a very important

signals that I want you to understand

very important signals here we have the

bat temperature or battery temperature

we have the acmb data and ASB clock so

right now I will explain to you what ISB

data ASB clock andb temperature and why

we use this kind of signals and what is

the purpose of the signals so before

explain these three signals let's first

take the measurement in the motherboard

so for ASB temperature we going to find

it in the p number four of the battery

connector ASB data in p number five

clock in pain number six we going to

find 3.3 Vol so let's check the

motherboard and then come back and

explain these three signals so in the

motherboard this is the battery connect

conector here and we have this Mark here

do you see this triangle means this is

the PIN number one pin number two three

4 so p number four is

forb temperature we have to find 3.3 Vol

let's check we have 3.3 volt so pin

number five this is as MB data we have

to find 3.3 Vol as you can see in the

multimeter and the pin number six is for

the clock 3.3 volt so we have the 3.3

volt in these three pins so good once we

check the three signals we find 3.3 volt

let's now explain it what is the signals

so for battery temperature based on this

signal the siio will make sure that the

heat of the battery is within normal is

good it's not overhead because if the

battery is overhead it the siio will

shut down the charge I see working for

thep data of course the siio will know

about the state of the battery for

example what is the level of the battery

is it 50% 40% 90% Etc once the battery

for example reach 100% the siio will

know that the battery reach 100% so the

siio will send another signal called ASP

data for the charge IC to stop the

control signal so it will stop

generating the control signal to G of

this moset then the 12 VT will stop be

generating and for as clock we call it

clock or timing okay

timing this signal basically is the

clock signal because all component in

the motherboard need the clock you know

for synchronization in order to work

properly so we find that those signals

are good so here we have the step number

11 is good so guys right now let's

summarize what we have seen before so we

have seen that this is the DC jack okay

once the adapter is plugged the 19 volt

will pass here to drain off this mosfet

but it will not pass to this side so

until these two mosfets or switches

receive the E drive from the charge

circuit but before generating the AC

Drive the charge IC should receive some

inputs including the dcn 19 volt and

also the ACN about 1.2 Vol to 3.3 volt

for our example we find 1.3 volt so once

the charge IC receive the signal it then

then generate the E drive to the gate of

these two mosfets then the 19 volt will

pass to this side so we can get here the

B+ the B+ is the main voltage for the

whole motherboard it will be distributed

to all circuit in the motherboard and of

course we will get here 19 volt in the

drain of this mosfit these two mosfets

of course will generate the voltage to

charge the battery so once these two

signals and the AC Drive is generated

and the main voltage here is good the

charge IC will then generate the E okay

to the boss or the super iio so the

super iio we know that the voltage here

is managed 100% good so the siio will

generate a signal teing the charge I go

ahead and generate the low gate and the

uppergate for this two mosfets in order

to generate 12 volt for the battery in

order to charge the battery basically

and the B way we have here another

current sense resistor exactly like this

one but this one here its purpose is to

measure and to calculate the current

consument by the battery I have here

another tip why as you can see here we

have the part here the 12 volt will be

generate to charge the battery and we

have also here another feedback to this

IC this is basically we call it the

phase the phase here will let the IC to

know whether the 12vt is generated or

not if for example the 12 VT is not

exact for example let's assume we get

here 13 volt so this IC will readjust

this signal for Lower Gate and upper

gate in order to get the 12 volt the

exact voltage so after generating this

voltage we have also this three signals

that will be generated about the same

time we have the battery temperature in

order to know all about the the

temperature for the battery if the

battery is overheated this IC will shut

off this charge circuit we have thep

data to know about about the state and

the level of the battery andb clock for

timing or synchronization so guys now we

reach the most important chapter in this

video is to teach you every issue and

the probable component that can cause

this issue so let's begin with battery

not charging so battery not charging

means what exactly means the 12 V here

is not generated to this battery means

what EX exactly means it could be the

problem could be in this mosfit one of

these two mosfets it could be the short

circuit and of course when we talk about

short circuit this is the probable

component that could be shorted because

it is connected to the ground and also

this capacitor if this capacitor is

shorted the 12 volt will go to to the

ground directly to the ground not to the

battery or it could be the IC so if the

I is not generate the Lower Gate and the

upper gate so we cannot get 12 volt so

the battery will not be charged of

course we cannot see that the IC is bad

we should first check its input and the

most important input here is to check

the E okay is e okay present or not

because before generating the signal to

activate this to moset this IC should

first send the AC okay to the siio the

siio of course could could receive the

AC okay but if the siio is failed it

cannot send this signal so for this

problem about battery not charging it

could be this two mosfets it could be

this capacitor it could be the battery

itself if we have a bad battery it could

be the connector the battery connector

could be the charge circuit and it could

be the siio so so let's move on to the

next issue battery not detected so if

the battery is not detected

automatically it could be the problem

the battery itself or the motherboard

within the battery because the battery

contain a motherboard inside it it could

be this connector the battery connector

and it could be also the a iio or the

super iio why because battery not

connected this is the signal that tell

us if the battery is connected or not

asmp data so if we have a problem with

this signal means the problem could be

here in the isio so now let's move on to

the next issue laptop works on adapter

but not on the battery so when the

laptop works on adapter but not in the

battery means we have problem in the

side so it could be this m because this

is the switch for the battery of course

it could be the battery itself it could

be the battery connected but this is the

probable component that could be failing

you should always check this component

and also check this inductor because if

this component is failed the 12 volt

cannot pass to this side so the next

issue battery not recognized so for the

battery not recognize issue it could be

the battery of course it could be the

motherboard of the battery or the

connector try to clean the connector and

of course it could be the siio or

sometimes it could be out of Hardware

you can find a virus or a mware so you

can also check the software part so the

next issue the laptop power on just on

battery but not on adapter so in this

case we have problem here in this part

so when the laptop Powers using the

battery but not adap the problem could

be here especially this switch because

this one is for protection 19 volt can

pass to this side but this one is failed

so it will not pass here so we will not

get B+ but if the battery is good we

will get B+ so the problem could be this

one or could be also the charge I so

please for laptop only powers on with

battery check the switch and check the I

so the next failure laptop turn off we

unplugged easy so we laptop turn off we

unpluged go ahead and change the battery

or check this connector it could be

dirty the next issue battery drains too

quickly so when battery drains too

quickly means of course you have problem

with the battery or you have a short

circuit somewhere in the motherboard in

this case based on my experience if you

try another battery but the problem stay

the same try to clean the whole

motherboard because it could be dirty

and there is a lack of current somewhere

in the motherboard so try another

battery and clean the whole motherboard

especially the charge circuit the next

issue adapter connected not charging so

when the adapter is connected but no

char

of course it could be the battery is a

bad battery it could be disconnector

also you should caim the connector make

sure the battery is inserted correctly

to the motherboard or to the connector

so check also the DC jack or the power

jack and of course it could be the

charge IC that doesn't generate the

Lower Gate and the upper gate could be

this twoos fet and could be also the AIO

the next issue battery per percentage

stuck so when the battery P percentage

stuck in this case the problem could be

here with this signal asmp data means

the battery state is not reported to

this to to the siio means the problem

could be Ed in the siio or in the

motherboard within the battery Next

Issue laptop charging slowly so in this

case when laptop charging slowly it

could be the current that is generated

here is not enough for the battery or it

could be the battery itself or it could

be a dirty connector so but in this case

always try to check this mosfit you can

even replace this mosfit because this

mosfet has the purpose to increase the

current because it is connected to the

ground always the mosit that is

connected to the ground has the purpose

to adjust the voltage and the current so

try to check this mosit and also the

inductor could be the failed one and

also the current sensor resist so for

this kind of issue check the battery

motherboard the connector the current

sensor resistor the inductor and this

mosit so the next issue charging but not

increasing the percentage so here of

course always we have problem with this

signal because all about states of

motherboard this is the signal that is

connected to the motherboard in pin

number five here we have pin number five

so try to clean this connector and also

the isio could be the cause of this

failure so the next issue plugged in not

charging so for this issue plugged in

means the adapter is plugged in but not

charging it could be the adapter itself

it could be the D Jack it it could be

the charge IC it could be this thos fit

it could be the connector a dirty

connector or it could be the battery

itself the next issue inconsistent

charging Behavior inconsistent charging

Behavior always refer to this this is a

very important signal SMP data assess

the state of the battery so for this

problem inconsistent charging Behavior

it could be the Super iio or could be

the motherboard inside the battery means

the battery so the next issue laptop

charging light blanking not showing so

in this case it could be the siio the

isio is the first cause for this case

the next issue laptop doesn't recognize

the charger so for the laptop doesn't

recognize charger it could be the

charger itself this kind of issue is

usually happen in the deal laptops but

it could be the D Jack the charger it

could be the IC itself doesn't recognize

the charger also it could be the siio

the last issue power adapter overheating

so when you have we have the problem of

power adapter is overheating of course

we have to use another power adapter to

make sure if the power power adapter is

bad or not but it could be also the

charge I see so thank you very much guys

I hope that you enjoyed the video please

don't forget to subscribe and hit the

Bell icon like and share the video thank

you very much and see you in the next

video