HP ENVY 17 Motherboard Short help please

[harshana]

Re: HP ENVY 17 Motherboard Short help please

yes I checked between pin 3 and metal tab.

can you check the attached photo. the marked part was heating.

[mon2]

Re: HP ENVY 17 Motherboard Short help please

This is the CPU & PCH in a single package. It is the most sensitive and lowest voltage rail device on the board.

If this part received a hit from the main power rail then this critical part is very likely dead. It is not cost effective to replace this part and requires a complex BGA rework station to remove and replace with another.

So this review effort may not fix this logic board.

The readings of the mosfet (4 pin) are too low and are shorting. You can remove this part off the logic board and then check if the short remains or not by checking only the pads on the board. However, very likely the CPU is dead.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

This is the CPU & PCH in a single package. It is the most sensitive and lowest voltage rail device on the board.

If this part received a hit from the main power rail then this critical part is very likely dead. It is not cost effective to replace this part and requires a complex BGA rework station to remove and replace with another.

So this review effort may not fix this logic board.

The readings of the mosfet (4 pin) are too low and are shorting. You can remove this part off the logic board and then check if the short remains or not by checking only the pads on the board. However, very likely the CPU is dead.

1st thing, You are correct. that mosfet has fried. however I removed it. on the other hand, the pad is still short to ground.


Actually at the beginning I found a bad cap and I removed it. after that the fan worked. however when I connect the board to display and power on the second time, I shorted 3vpcu to ground.(I wanted to short power sw.it was pin 6 on that connector. but I did it on pin 1)

After that I saw the short again.

What do you thing? Is this hopeless???

[mon2]

Re: HP ENVY 17 Motherboard Short help please

Which pad on which part is shorted to ground ?

What is the exact resistance you are measuring ?

If you shorted a power supply rail to ground, that may be ok but if the CPU rail saw anything higher than 1v then then the CPU / PCU (single package) is dead.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Which pad on which part is shorted to ground ?

What is the exact resistance you are measuring ?

If you shorted a power supply rail to ground, that may be ok but if the CPU rail saw anything higher than 1v then then the CPU / PCU (single package) is dead.

see the attachment. It's CN5 which is power on connector.

I had to short pin 6 to ground to turn on the board. But I shorted pin 1 to ground.

[mon2]

Re: HP ENVY 17 Motherboard Short help please

Hmm. If that is all you have done then I think there may be some hope. We still need to check but..

With the power on, what is the voltage of the +3VPCU rail on pin #1 of this connector ?

Also check the points in the attachment.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Hmm. If that is all you have done then I think there may be some hope. We still need to check but..

With the power on, what is the voltage of the +3VPCU rail on pin #1 of this connector ?

Also check the points in the attachment.

after this new issue, The board doesn't power on. When I check values in my power supply. Its voltage has drop to below than 1v(as I know it should be 19v)

So how I test this 3v regulator???

[mon2]

Re: HP ENVY 17 Motherboard Short help please

My apologies. I think you removed the 2nd mosfet?

That mosfet needs to be replaced as it was shorted.

Can you confirm?

[harshana]

Re: HP ENVY 17 Motherboard Short help please

My apologies. I think you removed the 2nd mosfet?

That mosfet needs to be replaced as it was shorted.

Can you confirm?

yes I removed It. so it needs to be replaced. But on the other hand when I check the resistance between ground and the pad on pcb which should connect to the pin3 in 2nd mosfet, Its value is around 0.7ohms. which is very low.

So what do you think, Is it still possible to connect it to the power and check voltages of that 3v regulator???

[mon2]

Re: HP ENVY 17 Motherboard Short help please

No. That is a very low resistance. Something downstream is causing this short condition.

Can you measure the resistance of the removed mosfet?

It may be ok or may be shorted.

If you inject 1 volt onto the rail that should have received 19v, who is heating up? Nothing higher as a mosfet later on the board could be leaking and will reach the cpu core and cause damage.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

No. That is a very low resistance. Something downstream is causing this short condition.

Can you measure the resistance of the removed mosfet?

It may be ok or may be shorted.

If you inject 1 volt onto the rail that should have received 19v, who is heating up? Nothing higher as a mosfet later on the board could be leaking and will reach the cpu core and cause damage.

When I check removed mosfet, It has very low resistance which means Its shorted.

On the other hand when I inject 1v no one is heating up. I tried to inject 1v up to 3A. I see the board take whole 3A. But no one heating up.

What should I do?

[mon2]

Re: HP ENVY 17 Motherboard Short help please

Someone is consuming this current. That is, this is 3 watts of power so some one should be warm to hot to the touch.

Can you pour some alcohol on the cpu and check if it is evaporating?

That is the biggest concern. If it is heating, the cpu is defective. If not, there could be a bad cap or another defective part on the logic board.

Here is a video doing the same...worth watching or a quick skim through.

https://youtu.be/_i1wRxRuwxs

Still recommend to keep the voltage low till we know for sure if the cpu is safe.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Someone is consuming this current. That is, this is 3 watts of power so some one should be warm to hot to the touch.

Can you pour some alcohol on the cpu and check if it is evaporating?

That is the biggest concern. If it is heating, the cpu is defective. If not, there could be a bad cap or another defective part on the logic board.

Here is a video doing the same...worth watching or a quick skim through.

https://youtu.be/_i1wRxRuwxs

Still recommend to keep the voltage low till we know for sure if the cpu is safe.

Which pad should I inject voltage?? 3v Inductor or somewhere else? Can you suggest by seeing schematics please

[mon2]

Re: HP ENVY 17 Motherboard Short help please

See attached. You can inject anywhere you see the VIN label.

For example, PU11, inductor PL18, either side is ok.

Use 1 volt @ 3A (or higher current is ok). For now, we want the voltage to remain low. Someone should start to heat up.

Check if PU11 or the CPU is getting warm / hot while you inject the voltage.

[reformatt]

Re: HP ENVY 17 Motherboard Short help please

Thermal camera, inject 1V, see what heats up. Likley a dead PCH/CPU, especially if you have dual short on 3.3V and 1.05V rails.

Despite what you see on YouTube, we don't usually get money for jam jobs like a shorted cap. Dead CPU's are the most common unfortunately.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

See attached. You can inject anywhere you see the VIN label.

For example, PU11, inductor PL18, either side is ok.

Use 1 volt @ 3A (or higher current is ok). For now, we want the voltage to remain low. Someone should start to heat up.

Check if PU11 or the CPU is getting warm / hot while you inject the voltage.

I see very light heat on both pu11 and cpu under 5A which I can inject max from my power unit.

Is that means Its over ???

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Thermal camera, inject 1V, see what heats up. Likley a dead PCH/CPU, especially if you have dual short on 3.3V and 1.05V rails.

Despite what you see on YouTube, we don't usually get money for jam jobs like a shorted cap. Dead CPU's are the most common unfortunately.

Actually I don't have a thermal camera. I started this stuff as a hobby. however I was able to detect very little heat using petrol test.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Any Luck?

[mon2]

Re: HP ENVY 17 Motherboard Short help please

Remove all power.

What is the resistance to ground of the 1.05V rail?

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Remove all power.

What is the resistance to ground of the 1.05V rail?

0.7ohms