HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

[loser18]

Hey there...

My problem is as described in title...

I've got no DC jack light, when charger is plugged in. After presing power button the DC jack LED blinks 3 times and that's it.

So measured PU2 & PIN6 (ACDET) is only 2.7V...All other voltages on PU2 seems to be OK...
Voltage on PR55 is 19V on one side & 2.7V on the other one...

PU2 (BQ24728) voltages:

PIN1=19V
PIN2=19V
PIN3=19V
PIN4=25V
PIN5=3V
PIN6=2.7V???
PIN7=0V???
PIN8=3.3V
PIN9=3.3V
PIN10=3.3V
PIN11=2.8V
PIN12=2.8V
PIN13=2.8V
PIN14=0V (obviously AS GROUND)
PIN15=0V
PIN16=6V
PIN17=6V
PIN18=2.7V
PIN19=2.7V
PIN20=19V

Also tried to re-flash BIOS SPI & replaced PQ16 & PQ17...

Any help would be appreciated...Thanks

[Stevie2001]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

Hey there...

My problem is as described in title...

I've got no DC jack light, when charger is plugged in. After presing power button the DC jack LED blinks 3 times and that's it.

So measured PU2 & PIN6 (ACDET) is only 2.7V...All other voltages on PU2 seems to be OK...
Voltage on PR55 is 19V on one side & 2.7V on the other one...

PU2 (BQ24728) voltages:

PIN1=19V
PIN2=19V
PIN3=19V
PIN4=25V
PIN5=3V
PIN6=2.7V???
PIN7=0V???
PIN8=3.3V
PIN9=3.3V
PIN10=3.3V
PIN11=2.8V
PIN12=2.8V
PIN13=2.8V
PIN14=0V (obviously AS GROUND)
PIN15=0V
PIN16=6V
PIN17=6V
PIN18=2.7V
PIN19=2.7V
PIN20=19V

Also tried to re-flash BIOS SPI & replaced PQ16 & PQ17...

Any help would be appreciated...Thanks

Best thing is to get your self a dc power supply works flawlessly it is a must bench supply.

With charger it can inject volts and if anything is blown inside the laptop then it cannot do anything further but with dc power supply it will reverse the power inject the voltage,this way the bad component will heat up and you can use your
fingers
freeze spray
alcohol
thermal camera

to spot it and replace it,youtube dc power supply repair learn from it very good to diagnose.
of course you use the multi-meter but its long process.
thermal camera is what you can use to find faults using just the original adapter.

change pu3 ISL6277

[loser18]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

THX for reply Steve...

I've got a professional bench PSU already & do well understand electronics circuitry...The technique you're describing is good for "dead shorted" components, however my issue issue is different...

[Stevie2001]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

THX for reply Steve...

I've got a professional bench PSU already & do well understand electronics circuitry...The technique you're describing is good for "dead shorted" components, however my issue issue is different...

change pu3 ISL6277

[loser18]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

change pu3 ISL6277

You must have wrong schematics as PU3 is different chip in my one...Also ISL6277 got nothing to do with charger detection...

[Stevie2001]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

You must have wrong schematics as PU3 is different chip in my one...Also ISL6277 got nothing to do with charger detection...

your voltage is wrong so isl is main problem.

PU8
ISL6277A

[loser18]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

your voltage is wrong so isl is main problem.
can u share shematic

There's schematic...

[Stevie2001]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

there's schematic...

pu8
isl6277a


change this guy
should look like this but pu8 defo

[loser18]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

pu8
isl6277a


change this guy
should look like this but pu8 defo

This chip supplies voltages only when mobo is in S0 state & that's completely irrelevant to me...It's got nothing to do with charging circuit...

[Stevie2001]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

This chip supplies voltages only when mobo is in S0 state & that's completely irrelevant to me...It's got nothing to do with charging circuit...

try it5

this chip controls voltages and if its short then you will get wrong voltages reading in some area or missing voltage.
the blinking led comes from this ic

[loser18]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

try it5

this chip controls voltages and if its short then you will get wrong voltages reading in some area or missing voltage.
the blinking led comes from this ic

Replaced just for curiosity but the issue is still the same...

[SMDFlea]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

PIN6 (ACDET) is ok .

[loser18]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

PIN6 (ACDET) is ok .

So why I've got 3 blinks on DC Jack? I thought it's caused by charger not communicating with charging IC or KBC properly...Also can you PLS share the BQ24728 datasheet?Tried to google but couldn't find it...

[Stevie2001]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

https://www.badcaps.net/forum/showthread.php?t=55032

[loser18]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

Ok...

So the issue seems to be KBC (U14) or +3V rail as reads only 1.8V on PIN11 (VCC)...
I'm tired AF, so will update tomorrow...

[mcplslg123]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

Have you checked resistance to gnd on vcc pin of kbc?? Something must be pulling the voltage down from 3v to 1.8 v.

After a proprer measure you can try removing the kbc and then powering on mb(without kbc soldered) and observe the differences.

[mcplslg123]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

try it5

this chip controls voltages and if its short then you will get wrong voltages reading in some area or missing voltage.
the blinking led comes from this ic

Dear Steve, Dont give suggestions which have no logic. Its a technical forum and there is no compulsion for anyone to comment without understanding it and thereby diverting the thought process in troubleshooting.

Dont be offended by my criticism-its in your interest only.

[SMDFlea]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

Check PU6 and PQ35

[loser18]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

KBC Voltages:

PIN71=0.8V???
PIN11=1.8V???
PIN74=3.3V
PIN127=3.3V
PIN26=3.3V(assume all other VSTBY have correct voltage)

Resistance on PIN11 is about 114KΩ

[loser18]

Re: HP 15-n027sa DA0U92MB6D0 not detecting charger / doesn't turn on

I was giving you wrong voltage of PIN 11 on KBC...I was reading PIN12 instead...Just checked it under microscope...Really sorry about that...

KBC:

PIN11=0V
PIN12=1.8V

The +3V should be suspend voltage so 0V is correct...