HP ZenBook 17 G4 not turning on

[DeniS182]

Hi all,
I have here this laptop. When dc adapter is connected, led near dc port is ON and after power button is pressed nothing happend. 19v is present, 5v is on power button. I found PL39 shorted to ground 0.5ohm. But i don't know what voltage is this rail. I desolder PJP2 jumper and tried inject 1V from my power supply to find something hot but my power supply after repair can supply only 0.7A when voltage is set to 1V. (Of course when I short probes its only 0.7A) and this current is too low to heat bad component and I dont't have thermal camera.

Please have someone schematic or something what help me?

Thanks

Board is CPW70 LA-E171P Rev : 1.0

[mon2]

Re: HP ZenBook 17 G4 not turning on

Remove all power. Meter in resistance mode (2k scale).

Check resistance to ground for each coil on the board. You may have a faulty cap on the rail.

Checking for a low resistance reading (for example a few hundred ohms is considered low for some of the higher voltage rails like 3v3 / 5v0).

The CPU / GPU rails will be low voltage and low resistance is ok but post such findings.

You can use alcohol instead of a thermal camera - we do this all the time. The alcohol will mist up from the heat due to the excessive current draw.

Try not to inject voltage till more is known about the logic board as a bad short could kill the CPU / PCH (aka low voltage devices).

[DeniS182]

Re: HP ZenBook 17 G4 not turning on

Thanks for answer.
I measured it like that, I found only this rail with too low resistance and I also mean this is cap or something in short. And I know CPU/PCH/GPU power rails are lower in ohms, but this is too low.ANd I use alcohol sometime but with low current which can I deliver with my bad power supply (0.7A) is hard to find spot where is hot.. I need to know what this rail is, which voltage I can inject here, my power supply works fine in higher voltage like 2-3V only, when I have here 1V it not work..

[EdwardGeo]

Re: HP ZenBook 17 G4 not turning on

Hi all,
I have here this laptop. When dc adapter is connected, led near dc port is ON and after power button is pressed nothing happend. 19v is present, 5v is on power button. I found PL39 shorted to ground 0.5ohm. But i don’t know what voltage is this rail. I desolder PJP2 jumper and tried inject 1V from my power supply to find something hot but my power supply after repair can supply only 0.7A when voltage is set to 1V. (Of course when I short probes its only 0.7A) and this current is too low to heat bad component and I dont’t have thermal camera.

Please have someone schematic or something what help me?

Thanks

Board is CPW70 LA-E171P Rev : 1.0

look at images

PL39 is 3.3V

[DeniS182]

Re: HP ZenBook 17 G4 not turning on

Thank you for the pictures. Problem is in CHipset. I check the whole board, chipset is hot.