HP 17 ( Quanta R63 ) no power with AC adapter

[delphi_firebird]

Hello,
Can you guys help me with my Laptop HP 17 model Quanta DA063MB6F1 wich wont turn on ac adapter pluged in (AC LED off ) but work fine with battery.
after many hours trying to figure out the problem, i ended up finding that the voltage on ACDET is oscillating between 1.6v and 2.6v

PU5 BQ24738 need at least 2.4v on ACDET to work , so i tried to inject this voltage with power supply , in this case , the AC LED turned on , and i was able to start up the motherboard .

i checked the voltage devider around ACDET is OK .
resistence to ground of ACDET is ok ( i find the same value comparing to a working motherboard )

i have changed PU5 , the same problem .

I hope some body can find the solution .

thank you by advance

[piernov]

Re: HP 17 ( Quanta R63 ) no power with AC adapter

PQ3 is being activated, that's why the voltage on ACDET gets lowered to 1.6V.
Measure the voltage on PQ3 gate, if it's high you'll have to figure out why.

[delphi_firebird]

Re: HP 17 ( Quanta R63 ) no power with AC adapter

Thank you piernov for your quick answer .
You are right PRWSRC is oscillating causing PQ3 being activated ...
but I do not understand why !!
Any suggestion ?

[piernov]

Re: HP 17 ( Quanta R63 ) no power with AC adapter

First make sure you're using a working original HP power brick with the correct power rating.
Check voltage on AD_AIR.

[delphi_firebird]

Re: HP 17 ( Quanta R63 ) no power with AC adapter

the motherboard is fixed .
PR57 was OL , so 0v on PQ4 gate .
Thank you very much @piernov, i appreciate your tips .
see u