HP G62-b24ST no power, blinking light

[tomodachi]

Hi all,

I just had a G62 today with no power fail,
As I check, when plug in adaptor, 19 volt is not stable and constantly changing on motherboard, and power led near power button is blinking, which making me think it is a short component problem, checked all mosfets and diodes on mobo and no trouble found then desoldered all jumpers of 19V in all sections to find out but no change, lately tried to take out CPU & RAM s but problem goes on,
did anyone faced this fail before or anyone can link me schematic ?
I m uploading 3 pictures including both sides and HP mobo part number,
Thanks in advance,

http://uploadpic.org/v.php?img=LUiWxo8MjK
http://uploadpic.org/v.php?img=lHnAqHKT4U
http://uploadpic.org/v.php?img=oTe9J3kGM3

[mattbrad2]

Re: HP G62-b24ST no power, blinking light

Constantly changing? What ranges? On the 19v rail, it's usually all or nothing. Highly unlikely something is causing it to fluctuate. This series has a horrible problem of the battery / power management IC going bad. Depending on the board, it'll be TI or ISL. Are you getting 3v from at least one of the battery charging terminals?

[tomodachi]

Re: HP G62-b24ST no power, blinking light

Constantly changing? What ranges? On the 19v rail, it's usually all or nothing. Highly unlikely something is causing it to fluctuate. This series has a horrible problem of the battery / power management IC going bad. Depending on the board, it'll be TI or ISL. Are you getting 3v from at least one of the battery charging terminals?

yes, I can see 3.3V on charging terminals

[mattbrad2]

Re: HP G62-b24ST no power, blinking light

yes, I can see 3.3V on charging terminals

Then your problem is not with the 19v rail. Your 3v buck controller is doing its job however the 5v rail is probably your problem. Often these are both controlled from the same PWM. ISL, TI or Maxim. A schematic will help you locate the correct one but often times they are located near the battery terminals or at the DC jack.

[tomodachi]

Re: HP G62-b24ST no power, blinking light

Then your problem is not with the 19v rail. Your 3v buck controller is doing its job however the 5v rail is probably your problem. Often these are both controlled from the same PWM. ISL, TI or Maxim. A schematic will help you locate the correct one but often times they are located near the battery terminals or at the DC jack.

Thanks for helping matt, I will check intensively and let you know result,

Best regards

[shacker]

Re: HP G62-b24ST no power, blinking light

hi all,
do you have solved?
thanks.

[tomodachi]

Re: HP G62-b24ST no power, blinking light

hi all,
do you have solved?
thanks.

Been a long time and I m not sure if I was succeeded or failed about that mobo, sorry man.

[jakobsen]

Re: HP G62-b24ST no power, blinking light

Hi
I have a G62 b36eo - with allmost same problem.

It works fine when on battery - But plug in AC has no effect:
no light in dc jack - no response at all.

I have found schematics and tryed debugging a bit.

1. When AC pluged in, m31aacin keeps oscillating on/off

Any common error to check around the max8731 power mm ic?

Regards Jørgen
copenhagen Denmark

[loser18]

Re: HP G62-b24ST no power, blinking light

OK...

Pretty similar problem HERE:

HP G62-107sa
Quanta AX1 ( DA0AX1MB6F0 )

Power LED light (on power connector) is OK...
When switch on power board light for a sec. than cut off...
NO fan spinning...


1.After inspecting the mobo found the PL11 is burnt & PR248 had some residue (assume from blown PL11)
2.Changed PL11 (R56D 752s) for (R56 948H6X) here I'm not sure if they're compatible...
3.Checked the BIOS voltages=looks OK...
4.Checked 2 MOSFETS around (PQ64 & PQ65)
5.PQ65 getting 19V on drain = IS IT NORMAL???
6.NO VOLTAGE ON PQ64 DRAIN = IS IT NORMAL???
7.Tested PU1 & pin20 (LGATE) gives me 0V
8.IF PU1 is bad (RT8152C) is there any alternative part as can't get this PMIC...


ANY HELP WOULD BE APPRECIATED!!!THX!!!

[leiangelo5]

Re: HP G62-b24ST no power, blinking light

hi guys. can i have a copy of the schmatics an boarview for this laptop. I have the same problem. thankyou

[razor_amd]

Re: HP G62-b24ST no power, blinking light

Here