HP 250 G9 - short circuit 100%

[Cicciotest]

Good morning guys.
I made a mess. I opened the new laptop, replaced the NVMe SSD, and closed it. When I plugged in the power cord, I saw the orange LED glow dimly several times, so I immediately unplugged it. I could also hear a strange buzzing sound coming from the laptop. Then I opened it again, and only later noticed that underneath the SSD was an aluminum plate that touched practically all the underlying components... what a disaster. I still don't understand how I didn't notice. Anyway...

I thought, okay, I'll just remove the plate and go. But now the power LED won't even turn on. It's completely dead, no lights, no LEDs.

I tested the power supply with a multimeter and it's perfect at 19.9v. I tried a second HP power supply I have at home for good luck with same voltage + ampere, but the result is the same: no power LEDs and no feedback wen i press power button.
I also removed the battery and tried a reset with the power button. I left it unplugged all night without the battery and cable, but the result this morning is the same.
So I made one or more shorts down there...
With the multimeter I can see that the 19/20V is reaching these red points, but then I don't know what to do and I can't figure out which component needs replacing.... Can you give me a hand, please?


This is the motherboard:

[Cicciotest]

Here a zoom of power entrance area and SSD area where i placed the ssd plate... hope you can see better.
in the rear side of the motherboard there is nothing, is completely smooth.

[Cicciotest]

THE MOTHERBOARS MODEL IS: IPA50 LA-K203P REV2.0

[ianbak]

The power from the charger is reaching the mother board - that's what you're measuring on the red wires.
There's a pinned thread here https://www.badcaps.net/forum/troubl...arging-circuit that explains where things go from there.

[Cicciotest]

The power from the charger is reaching the mother board - that's what you're measuring on the red wires.
There's a pinned thread here https://www.badcaps.net/forum/troubl...arging-circuit that explains where things go from there.

I read it but I can't translate the diagrams very well, in any case I understood from there, that I have to test the MOSFETs of the main power circuit, I tested these and they are ok:
there is nothing else on this side.


Instead on the top side, near the power connector, I tested these small mosfets but I got some strange readings on two of the 3:


Also on this side these MOSFETs give me continuity:

[Cicciotest]

In the meantime I tested the continuity in the coils, the red ones give me continuity, the green ones are ok:
Those mark in red with arrow in CPU, i think that are OK becouse yes, there is continuity but the resistance value is really low.
Also the Fuse (FU1 753J) is ok.

[Cicciotest]

i think that there is too many componente damaged here... too many componente damaged.
Mosfet and Ceramic capacitor that responds with low resistence, i have to remove all of them and test out of the board... anyway... i have to give up...

[mon2]

You are measuring the multiphase cpu power rails. This region, by design, will be with a low resistance. What is the exact resistance you are measuring here?

ps: I am travelling through Asia on business and have limited time to view the posts till my return. If you read 0 ohms here to ground then the cpu / pch is very likely shorted (dead).

[Cicciotest]

Hi, thanks, yes, I figured those were CPU-related, so I ignored them. No, I don't have 0 ohms, but something like 0.6-0.4 ohms, sometimes even 1 ohms, but I saw up close that all those MOSFETs are buck converters and therefore share pins, hence the continuity.

Now... I should start again from the power connector. But I don't know which components to test and how to do it properly.
If I had a thermal imaging camera, I probably would have already solved the problem by injecting 1.2 volts into an input point.

[Cicciotest]

Today i've spend some time to test ceramic capacitors, those in RED are all in 0ohm and continuty, maybe i write the code of the label in the motherboard:

Beginning from LEFT-BELOW in clock order, so, going up and then in the right side:
- PL12
- PL303 + PL304
- PL305
- PLG02
- LL2
- PLM2
- PL2501
- PL13 + PL14
- L5 + L6

Is is really strange that all thees line of capacitor give 0 ohms, sems all under a circuit that is in short... but why? Are really all of these in shorts or maybe is there a component before of them that put in short the circuit?
Below i attach a clean motherboard photo:

[Cicciotest]

Sorry, the red ones are in continuty and 0 ohms, and i've listed them with their code.
All the green ones sems to be good.