HP ZBook 17 G3 Mobile Workstation LA-C391p won't turn on and the power light is blinking

[my dodge]

Hello
I was looking for a schematic or board view but unfortunately I didn't find anything.
By connecting the drain and source of pq58, the device turns on and works perfectly, but the battery doesn't charge, and I don't know the path of the circuit to the MOSFET.
Is the problem with the adapter? Or is there a problem with the MOSFET activation circuit?
Please guide me.
Thank you.

[mon2]

From zbook 15 G3 schematic

[my dodge]

Hello
I was looking for a schematic or board view but unfortunately I didn't find anything.
By connecting the drain and source of pq58, the device turns on and works perfectly, but the battery doesn't charge, and I don't know the path of the circuit to the MOSFET.
Is the problem with the adapter? Or is there a problem with the MOSFET activation circuit?
Please guide me.
Thank you.

I reached the BQ24780s

IC by following the path of the pq58 ( TPCA8057-H

) pins.

[mon2]

The above schematic is the same as for your board.

Remove all power. Meter in resistance mode. Measure the resistance across the mosfet pins to check if they are leaking.

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Each measurement must be hundreds of k ohms or higher. Otherwise the part may be leaking and needs to be replaced. If found, flux and remove the part and allow it to cool. Then measure in the same way while the part is on your work table. Suspecting that the 1st DCin mosfet is defective.

Carefully, measure the following voltage to ground for the following pins of interest with the adapter:

ACDET ; pin 6
REGN ; pin 24
VCC ; pin 28
ACDRV ; pin 4

[my dodge]

The above schematic is the same as for your board.

Remove all power. Meter in resistance mode. Measure the resistance across the mosfet pins to check if they are leaking.

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Each measurement must be hundreds of k ohms or higher. Otherwise the part may be leaking and needs to be replaced. If found, flux and remove the part and allow it to cool. Then measure in the same way while the part is on your work table. Suspecting that the 1st DCin mosfet is defective.

Carefully, measure the following voltage to ground for the following pins of interest with the adapter:

ACDET ; pin 6
REGN ; pin 24
VCC ; pin 28
ACDRV ; pin 4

I have already removed the MOSFET from the board and checked it with a multimeter
In diode mode with gate excitation, the source and drain values are the same in both prop positions and are about 0, and again with reverse gate excitation and the MOSFET is turned off, this value becomes a diode, which is o.l on one side and about 0.5 on the other

But in ohm mode, the MOSFET between the drain and source shows about 3.9 M ohm on both sides, which is halved when the gate is excited and the MOSFET is turned on, so to speak, and becomes about 1.5 Mohms.

The MOSFET appears to be healthy.

[mon2]

Review PQ56 - the 2nd dcin mosfet.

[my dodge]

The above schematic is the same as for your board.

Remove all power. Meter in resistance mode. Measure the resistance across the mosfet pins to check if they are leaking.

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Each measurement must be hundreds of k ohms or higher. Otherwise the part may be leaking and needs to be replaced. If found, flux and remove the part and allow it to cool. Then measure in the same way while the part is on your work table. Suspecting that the 1st DCin mosfet is defective.

Carefully, measure the following voltage to ground for the following pins of interest with the adapter:

ACDET ; pin 6
REGN ; pin 24
VCC ; pin 28
ACDRV ; pin 4

But on the board and of course without a MOSFET, in ohm mode, the value between the source and drain is the same on both sides, approximately 400 kilohms, and for the gate, only when the negative probe is connected to the gate, we have a value of about 5.6 megaohms with the drain and about 4.96 megaohms with the drain, and in the positive probe mode with the gate, o.l is shown.

[my dodge]

Review PQ56 - the 2nd dcin mosfet.

Yes, definitely

I will check the voltages and let you know

[mon2]

Test the removed mosfet in resistance mode for:

source / gate
gate / drain

[my dodge]

Test the removed mosfet in resistance mode for:

source / gate
gate / drain

Surprisingly, in both modes, the probes only display O.L for both requested modes.

[mon2]

Is your meter an auto-ranging type or manual type for the resistance mode? If manual, select a higher scale till you have a measurement. In summary, we are confirming that each resistance check is hundreds of K ohms or more.

[my dodge]

Is your meter an auto-ranging type or manual type for the resistance mode? If manual, select a higher scale till you have a measurement. In summary, we are confirming that each resistance check is hundreds of K ohms or more.

It is Auto Range and the result of this last test was very surprising to me.

[mon2]

There is the possibility that the mosfet is defective and therefore reporting the same 'OL' resistance. Test against another known good mosfet to compare.

[Popitto86 repair]

Hi everyone , I have recently joined this forum because of this issue with my Zbook 15 G3.
Same problem : led on the power button blinking / flat battery and can't turn on the pc.
I saw on youtube a video about this same issue , and shorting a capacitor w a pair of tweezers solved the problem 4 me.
I wanted to share with you my experience hoping it is helpful 4u too
The capacitor I shorted is the white one under "PQ56" written on the motherboard ( see picture ) .
Now my zbook is charging fine.