Dell XPS 9510 LA-K411P Liquid damaged

[AJ847.63e]

Hi All,

Just wanted to get some advice on a XPS 9510 we have. Unit suddenly decided it no longer wants to turn on. Sometimes pressing the power button, it sits on keyboard lights no picture and boot loops a few times before shutting down. Other times it completely ignores the power button and does nothing. There is no light at the front of the laptop.
We are getting 20V on all 3 ports so the USB C PD communications working fine. We are getting 12V,3V3 and 5v so it seems like an issue quite late in the power sequence.


Removed the board and found dust corrosion around the following: PL2801 PC2828 (top right corner above the CPU) which looks like one of the CPU phases. Remarkably none of those components there read short. PL1600 & PL1602 (mid left corner above the second VRAM chip) were completely charcoal due to a shorted line, which seems to be caused by corrosion on a MLCC directly on the other side of the board through 6 via. I have not removed any caps yet though so can't say for sure.I did however remove both burned inductors and it is the bottom pad towards the DIMM slots that is shorted 0.7 ohm. There also is dust corrosion around the passives above UV22 (top left corner diagonally left from the third VRAM chip) and the two MLCCs read dead short which looks like the power regulation for the video memory.

Given that the corrosion is around the worst two spots on the board, CPU & VRAM, does anyone have known good readings of the CPU and video memory? This board's using GDDR6 Samsung. I don't want to dig into what's happened to find out congrats your GPU or CPU is dead.
I unfortunately have not been able to find the correct schematic for this board, only the LA-H331P which seems to be the previous year's model. No boardviews either.

I've attached two photos of the corroded areas for reference.

Thanks for the assistance.

[mcplslg123]

PL1600/1602 is VIN for PU1600. Remove PL1600/1602 and checck resistance to GND on both pads of PL1600/1602. Lets first check whether there is any shorting.

[AJ847.63e]

Thanks for the info. Removed both PL1600 & 1602 and found the second pin was shorted (pin closer to the RAM slot, apologies don't have the schematic, so I don't know whether it's pin 1 or 2).

Turns out the cap I thought was shorted was indeed shorted. The big MLCC that is directly on the other side of the board through the 6 vias next to the two burned inductors. Removed that cap and what do you know she's working!

Curious to know, what is that line for? Just want to try get a understanding of what happened and what caused it, and more importantly what could of been damaged and weakened in the process. She's working for now, even the 3050ti is showing up in device manager no dreaded error 48. But for how much longer.....?

[mcplslg123]

The IC marked BAA on the pic is silergy product used as DC-DC regulator. It can be configured to output 4V-23V,so very likely its either used for 3.3V/5V rail.
The cap is very important here and should be replaced. In the absence of schematic,try any cap rated for 25V and atleast 1uF(better to use 10uF/25V)

[AJ847.63e]

Ok thanks. The 3v3 and 5V rail were up when I took the board out so hopefully nothings else has been damaged in the process of the inductors going nuclear. Both inductors have been replaced along with the cap so this should be good to go.

Thanks again for your assistance.

[master3112]

Hello everyone,

I have a Dell XPS 15 9510 and the device won't start. I found out that there is no voltage at the BIOS chip Winbond 25Q16JWIQ. At the Winbond 25R256JVEN has 3.3V present. When I connect a power supply unit, the device has a current consumption of 0.05A. After 10 seconds the consumption sings to 0.002A. Does anyone know where the 25Q16JWIQ is supplied with power? Does anyone have a circuit diagram for the device?

Thanks

[master3112]

I have measured all voltages at all PIN of the ISL9538CH, as described in the article by reeluff.Link: https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/3213351-dell-xps-15-9510-la-k411p-nvdc-isl9538c-no-boot-no-charge#post3213351
My Results:
4 I have 15V instead of 12V
5 I have 14V instead of 10V
6 I have 10V instead of 7V
7 I have 1V instead of 2.3V
9 I have 1V instead of 2.3V
10 I have 10V instead of 7V
11 I have 10 V instead of 7V
12 I have 10 V instead of 12V
13 I have 0.2 V instead of 9V
31 I have 0V instead of 11.4V

I probably have no voltage at PIN 31 because my battery was not connected. The only noticeable deviation is at PIN 13, where I have 0.2V. Since all other voltages match the specifications from reeluff, I assume that the ISL9538CH is OK, or what do you think? Does anyone have any idea why the voltage at PIN 13 is different and what else I can check?
THX

[mon2]

If the voltage is not matching your golden sample list of voltages, remove all power -> meter in resistance mode (not diode mode). Measure the resistance to ground of pin #13. Post the measurement and the units of measure. One meter probe on pin # 13; other meter probe on ground (shield is ok). Even better if you post a pic of the meter face for a quick review.

[master3112]

I have measured the resistance at pin 13 of the ISL9538CH against ground. This is 3.493MOhm. See pictures. AJ847.63e have you already solved your problem? If not and you still have your device, we can take a few measurements on the board and exchange ideas.

[master3112]

I also measured the charging circuitry and noticed that the battery is not being charged. The battery voltage is 11.2V when it is not connected. When the battery is connected to the mainboard, without a power supply, the gate of the PQ1905 and also pin 31 of the ISL9538CH are 11.2 V (battery voltage). If I disconnect the battery and only connect the power supply unit, the voltage at the gate of the PQ1905 and also at pin 31 of the ISL9538CH is 12.5V. The voltage at the output of the PQ1905 is 0V. When I connect the battery and power supply, I measure 13.3V at the gate of the PQ1905. However, the voltage at the output of the PQ1905 and at the battery is only 11.2V. The voltage at the input of the PQ1905 is 12.56V. The device has a current consumption of only 0.045A and the battery is not charged. The resistance at the output of the PQ1905 to ground is 3.7MOhm. There is not a short. The PQ1905 is an B07P03 (see picture, but I could not find it anywhere. I could only find a B07N03, I don't know if this one is identical.) If there is a voltage at the input of the PQ1905 and also at the gate of the power controller ISL9538CH (pin 31) and the PQ1905 is OK, the battery should normally be charged, or not? Does anyone have any information on this? It does not explain why the 25Q16JWIQ does not receive a power supply. But it doesn't seem to be OK either.

[master3112]

I continued to look for faults and measured the transistors for the 3.3V and 5V voltage. I also measured and listed the gate voltage. I measured whether the 256MB Winbond 25R256JVEN is connected to this 3.3V rail. It is not. Maybe someone needs it.

[master3112]

I have also measured that 12V is present at the AKUN 650 (see photo.Does anyone have a datasheet for this IC?). The output is switched through to PIN 10 of the RAM memory. I assume that this is the power supply for the RAMs. I would expect 1.5V at the output, but I could not measure any voltage there. It is possible that this is only switched on at startup. Does anyone know which PIN the power supply for the RAM should be connected to? Is it PIN 10 as I assume?

[majkel_27@o2.pl]

Hello, I am asking for help in identifying the element marked as UZ7, system sot-23-8, symbol 516A5

[mon2]

Post a clear pic of the part. SOT23-5 package?

[SMDFlea]

I have also measured that 12V is present at the AKUN 650 (see photo.Does anyone have a datasheet for this IC?).

AKU* NB685GQ QFN-16 (3mm x 3mm) .Datasheet - https://www.monolithicpower.com/en/d...en/sku/NB685GQ

https://www.badcaps.net/forum/troubl...20#post1482820
Marking List April 2022 https://www.badcaps.net/filedata/fetch?id=2089349

[majkel_27@o2.pl]

Witam, proszę o pomoc w identyfikacji elementu oznaczonego jako UZ7, układ sot-23-8, symbol 516A5

[majkel_27@o2.pl]

Witam, proszę o pomoc w identyfikacji elementu oznaczonego jako UZ7, układ sot-23-8, symbol 516A5

another one was inserted in this place but it worked for 5 minutes and died, at the bottom of the photo there is 516A5 and there was one but I can't identify what it is

[majkel_27@o2.pl]

To powinny być ten sam układ