HP Omen 17-w104no dead PCH? Second opinion

[peku]

Hi,

First some laptop info:
Model: HP Omen 17-w104no
Motherboard: Quanta G38D
CPU: Core i7 I7-6700HQ (I think?)
GPU: nVidia GTX 1070

What happened: plugged in an old smartwatch for charging/syncing after years of no use, after a while computer just shut down, leaving a little white light at the power button. Pressing power after that, nothing happens. After opening up case and disconnecting/connecting battery, not even that white light appears, no light on the charging connector either.

I've tried diagnosing with a multi-meter and got some help on a Discord server from a dude who seems to know what he is talking about (might be reading this also, LOL) who said the evidence points to a dead PCH. But I thought I'd ask for a second opinion here if there's any hope or just take it for recycling.

Attached is a picture of the motherboard with voltages measured with charger connected and written with red font and then resistance measured with charger, battery, RAM and RTC battery removed and written with green font.

Do ask if other measurements are needed.

[ktmmotocross]

Re: HP Omen 17-w104no dead PCH? Second opinion

have u 3V on pwrbtn with goas to 0W when pressed?

[peku]

Re: HP Omen 17-w104no dead PCH? Second opinion

have u 3V on pwrbtn with goas to 0W when pressed?

Yes, 3.3V at the power button and 0.3V or so when pressed down.

[peku]

Re: HP Omen 17-w104no dead PCH? Second opinion

So I guess final verdict is it's dead and should be buried?

[myth77]

Re: HP Omen 17-w104no dead PCH? Second opinion

is that reading in ohm arround pch is 1 ohm? if yes, then its 99% your pch is dead and 1% some capacitor in that area is dead.

[EdwardGeo]

Re: HP Omen 17-w104no dead PCH? Second opinion

Hi,

First some laptop info:
Model: HP Omen 17-w104no
Motherboard: Quanta G38D
CPU: Core i7 I7-6700HQ (I think?)
GPU: nVidia GTX 1070

What happened: plugged in an old smartwatch for charging/syncing after years of no use, after a while computer just shut down, leaving a little white light at the power button. Pressing power after that, nothing happens. After opening up case and disconnecting/connecting battery, not even that white light appears, no light on the charging connector either.

I've tried diagnosing with a multi-meter and got some help on a Discord server from a dude who seems to know what he is talking about (might be reading this also, LOL) who said the evidence points to a dead PCH. But I thought I'd ask for a second opinion here if there's any hope or just take it for recycling.

Attached is a picture of the motherboard with voltages measured with charger connected and written with red font and then resistance measured with charger, battery, RAM and RTC battery removed and written with green font.

Do ask if other measurements are needed.

Smartwatch is usb device?
So problem comes from usb?


Make high quality photos of motherboard. Is there a schematic or boardview available for this motherboard?

Also keep in mind that HP has good short-circuit protection for most of external connections. But for internal connections (cables and flexes) in most cases are not.

Pch has 3.3v aux also, measure that line first

also when measuring something, first disconnect all cables attached to motherboard. then only AC\DC PSU connector use when measuring voltages.

[peku]

Re: HP Omen 17-w104no dead PCH? Second opinion

is that reading in ohm arround pch is 1 ohm? if yes, then its 99% your pch is dead and 1% some capacitor in that area is dead.

Yes, all green values are in ohms and both measurements around PCH are 1.

[peku]

Re: HP Omen 17-w104no dead PCH? Second opinion

Smartwatch is usb device?
So problem comes from usb?

Yes USB watch. Not of course sure but would be a strange coincidence if not related. The USB port I connected it to is just outside the attached picture on the right-hand side together with the audio in/out connectors. And also the power button cable goes through that little separate board with the USB port and then connects to the motherboard.

Someone somewhere mentioned (can't find the quote anymore) that a USB device goes "directly" to PCH and could in some unlucky cases kill it?

Make high quality photos of motherboard. Is there a schematic or boardview available for this motherboard?

I have not been able to find such documents. I'll see if I can get a good picture.

Also keep in mind that HP has good short-circuit protection for most of external connections. But for internal connections (cables and flexes) in most cases are not.

Pch has 3.3v aux also, measure that line first

also when measuring something, first disconnect all cables attached to motherboard. then only AC\DC PSU connector use when measuring voltages.

OK I'll check that tonight, thanks.

[EdwardGeo]

Re: HP Omen 17-w104no dead PCH? Second opinion

Someone somewhere mentioned (can't find the quote anymore) that a USB device goes "directly" to PCH and could in some unlucky cases kill it?

Data lines are diode protected, also they can have a ferrite protection and also ESD protection. the next thing - a lot of motherboards have dead usb 2.0 and keep working without hub oh hud line.

But if protection is dead, you need to check your watch connector first and cable if it does have a short or resistance it high. if there is no short, test with USB load tester. weak connection can burn shielding and only when hot enough, to short datalines.

I think the problem is at usb power protection circuit, or datalined diodes shorted to ground.

for example i do exidentaly shorted pci signals to ground, and after cleaning the gpu was working fine

[peku]

Re: HP Omen 17-w104no dead PCH? Second opinion

The watch itself works fine and charges/syncs on another computer. Also the USB port on the dead laptop does get power and I can charge stuff on it when AC is plugged in.

I now found the boardview for the motherboard but don't really know what to look for. Can I post it here?

[EdwardGeo]

Re: HP Omen 17-w104no dead PCH? Second opinion

The watch itself works fine and charges/syncs on another computer. Also the USB port on the dead laptop does get power and I can charge stuff on it when AC is plugged in.

I now found the boardview for the motherboard but don't really know what to look for. Can I post it here?

if you have boardview and schematic, you can post it


What is about voltages at coils?
Did you get high res images of board?

[EdwardGeo]

Re: HP Omen 17-w104no dead PCH? Second opinion

also test all mosfets (source and drain resistance) and (source and gate) maybe some of mosfets have failed

[EdwardGeo]

Re: HP Omen 17-w104no dead PCH? Second opinion

it seems like a short at 3.3v?

[peku]

Re: HP Omen 17-w104no dead PCH? Second opinion

Not sure if hi-res enough but a better, clean picture of the board attached.

Also boardview file which should be the correct one. The schematics is not the exact match but I guess pretty similar.

[EdwardGeo]

Re: HP Omen 17-w104no dead PCH? Second opinion

Check resistance of PL2002 in power off and power on. if coil will stop then you have a short before PU2001, if not then it could be a caps near PL2001 coil or other . also test for a short all capacitors near PU2001 and pc4049


Also check 3.3 Coil voltage after power on. also you can connect led foots. if it will blink you will know that short is there but nothing bad, the protection saved circuit.


But start from usb protection circuit. this one have a 3.3v power source

[EdwardGeo]

Re: HP Omen 17-w104no dead PCH? Second opinion

Also, you need first to have +3.3v +5v voltages to receive power ok status. after that pch, cpu, and other will request power. Your first image doesnt have 3.3v

[peku]

Re: HP Omen 17-w104no dead PCH? Second opinion

Check resistance of PL2002 in power off and power on. if coil will stop then you have a short before PU2001, if not then it could be a caps near PL2001 coil or other . also test for a short all capacitors near PU2001 and pc4049

Either I'm blind or PL2002 is missing from the board, shouldn't it be in the place marked with red arrow on attached pic?

[EdwardGeo]

Re: HP Omen 17-w104no dead PCH? Second opinion

Either I'm blind or PL2002 is missing from the board, shouldn't it be in the place marked with red arrow on attached pic?

this could be not used in your revision of board. Also keep in mind that attached schematic and boardview is not for this board.



Whats about 3.3v?

[peku]

Re: HP Omen 17-w104no dead PCH? Second opinion

But start from usb protection circuit. this one have a 3.3v power source

No voltages around U7500, no 3.3V anywhere.

[EdwardGeo]

Re: HP Omen 17-w104no dead PCH? Second opinion

No voltages around U7500, no 3.3V anywhere.

Unsolder PL2001 (3.3V coil) and measure resistance to ground at 200 ohm mode on multi-meter. do you have equipment and skills for it?

When PL2001 will be de-attached, measure resistance to ground of +3VS5_S and SY8208BSW pins

Also before desoldering measure all caps and resistors near PU2001 for a short. It seems that this motherboard doesn't have overcurrent protection, so PU2001 could be dead


IF COIL IS NOT CONNECTED, DO NOT INJECT VOLTAGE. THE CIRCUIT WILL BE CHANGED AND CAN HARM OTHER COMPONENTS, BECAUSE ONE OF RESISTORS CANT LIMIT CURRENT IF CIRCUIT HAVE CHANGED