HP ENVY 17 Motherboard Short help please

[harshana]

Motherboard Model: DAY31AMB6C0 REV C

I was able to find out the boardview and the schematics from the forum. I see there is a short but I can't find out where it is. all the 3v 5v 19.5 are short to ground. when I remove 3v step down regulator, 19v rail is okay but still 3v & 5v inductors short to ground but only LDO signal from 5v chip okay.

I injected 1v to 3v rail and I was able to see that CPU is heating.

Can you guys help me to fix this. I really want to fix this motherboard.

Special: I shorted power switch pin 1 to ground by mistake. Thats the cause to happen this. When I see schematic pin 1 is 3vpcu.

Anyone can help please???

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Anyone please ��

[SMDFlea]

Re: HP ENVY 17 Motherboard Short help please

Anyone please ��

Do you have a DC power supplt to inject voltage with

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Do you have a DC power supplt to inject voltage with

Yes I injected 1v with 3A

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Do you have a DC power supplt to inject voltage with

Here are the schematics and boardview

[MOD EDIT] Link to schematic -> https://www.badcaps.net/forum/troubl...b6c0-schematic

19v short solved when I remove PU11 chip. but still other power rails short to ground.

when I inject power to 3v rail, PU6 got heated. So I removed it and checked. So I removed that one as well. Then PU8 got heated. So I moved PU5,PU6,PU8.

Then I see that the CPU is heating.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

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[mon2]

Re: HP ENVY 17 Motherboard Short help please

Can you post the full details of how you are finding the above to be shorted ?

Remove all power -> meter in lowest resistance scale -> meter probe on the 3v rail; other meter probe to ground.

What is the exact reading to ground ? Post the measurement and also the scale used on your meter for this measurement. If possible, share a pic of the meter.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

When I power DC jack using power supply, It takes more than 2A. Thats how I detect the 19v rail short. will upload meter readings soon

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Can you post the full details of how you are finding the above to be shorted ?

Remove all power -> meter in lowest resistance scale -> meter probe on the 3v rail; other meter probe to ground.

What is the exact reading to ground ? Post the measurement and also the scale used on your meter for this measurement. If possible, share a pic of the meter.

Probe resistance: 0.4ohm

Scale: 200ohm (Digital Multi meter UT33B+)

PQ33(First Mosfet) Pin 1,2,3 -----> 0.7ohm

PQ20(2nd Mosfet) Pin 1 -----> 1.7ohm & Pin 3 ---->0.4ohm



PL21 (3v Rail Inductor) -----> 0.4ohm

PL20 (5v Rail Inductor) -----> 1.8ohm

PL16 (1.05 Rail Inductor) -----> 0.7ohm

PL12 & PL13 (+VGACORE according to schematics) -----> 10ohm

[mon2]

Re: HP ENVY 17 Motherboard Short help please

Probe resistance: 0.4ohm

Scale: 200ohm (Digital Multi meter UT33B+)

PQ33(First Mosfet) Pin 1,2,3 -----> 0.7ohm

PQ20(2nd Mosfet) Pin 1 -----> 1.7ohm & Pin 3 ---->0.4ohm

Ok. This helps.

Pins 1-2-3 are expected to be shorted together since each is the SOURCE cluster of pins. The readings are ok.

Pin # 4 = GATE.

Then pins 5-6-7-8 will be grouped together = DRAIN cluster of pins.

To check if your mosfet is shorted, check the following:

source (1-2-3) ; pick any of these pins with one meter probe
drain (5-6-7-8) ; pick any of these pins

note the reading and post it here. If you see '1' or 'OL' -> then select a higher meter setting till you have an actual value.

The '1' / 'OL' means the meter scale is too low and your resistance is higher than say 200 ohms, etc.

A low resistance reading = defective mosfet.

Next,

source (1-2-3) & gate (4) ; post the reading
gate (4) & drain (5-6-7-8) ; post the reading

Repeat for the 2nd mosfet as well.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Ok. This helps.

Pins 1-2-3 are expected to be shorted together since each is the SOURCE cluster of pins. The readings are ok.

Pin # 4 = GATE.

Then pins 5-6-7-8 will be grouped together = DRAIN cluster of pins.

To check if your mosfet is shorted, check the following:

source (1-2-3) ; pick any of these pins with one meter probe
drain (5-6-7-8) ; pick any of these pins

note the reading and post it here. If you see '1' or 'OL' -> then select a higher meter setting till you have an actual value.

The '1' / 'OL' means the meter scale is too low and your resistance is higher than say 200 ohms, etc.

A low resistance reading = defective mosfet.

Next,

source (1-2-3) & gate (4) ; post the reading
gate (4) & drain (5-6-7-8) ; post the reading

Repeat for the 2nd mosfet as well.

1st Mosfet = Source to Drain -----> 8.8kohm

2nd Mosfet (it only has 4 pins) = Source to Drain -------> 1.5ohm

see the attached photo also please

[mon2]

Re: HP ENVY 17 Motherboard Short help please

I am not familiar with this logic board but for sure the 2nd part is not the mosfet for the DCin connection.

Can you zoom / look around the DC in power jack on your logic board ?

The ~19v will enter there -> then look for parts like the '#1' in your post = that is a mosfet and the 2nd mosfet will be similar.

We are interested to inspect the first 2 x DCin mosfets for this review.

Post pics so we can be sure.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

My mistake.

2nd Mosfet (it only has 4 pins) = Source to Drain -------> 0.5ohm

not 1.5

[harshana]

Re: HP ENVY 17 Motherboard Short help please

According the schematics. thats the 2nd mosfet. Actually I'm new to this. Am I wrong?

[mon2]

Re: HP ENVY 17 Motherboard Short help please

Ok. Just re-read this thread - found the schematic..hold for a few.

My bad...you are on the right track and are indexing the correct mosfets.

See attached for the pinout & datasheet for the 2nd mosfet.

Can you confirm that you are using the TAB and the right pin for the SOURCE & DRAIN resistance checks ?

This is reading @ 0.5 ohms ?? (you are on the lowest 200 ohm scale on your meter ?)

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Here is the board with DC jack

[piernov]

Re: HP ENVY 17 Motherboard Short help please

Why waste time on a dead PCH? (and many other things)

[mon2]

Re: HP ENVY 17 Motherboard Short help please

I injected 1v to 3v rail and I was able to see that CPU is heating.

Special: I shorted power switch pin 1 to ground by mistake. Thats the cause to happen this. When I see schematic pin 1 is 3vpcu.

The CPU is very likely fried.

[harshana]

Re: HP ENVY 17 Motherboard Short help please

Yes I can guarantee that I checked resistance between pin 4 and pin 3. I entered it as 1.5 by mistake. actual reading was 0.5ohms.

and also my scale is 200ohm

What did you mean by TAB?? I didn't get it.

[mon2]

Re: HP ENVY 17 Motherboard Short help please

TAB is the middle of the 3 pins.

So there is the LEFT, MIDDLE pin (broken) but is the metal TAB that is soldered and large in size, RIGHT pin.