Samsung EVO 850 overvoltage repair

[Tom33]

Hello,

I am new here in the forum and I would be very grateful if someone could help me with my question.
I am from austria so please excuse my bad english, i give my best.

The Story:
I bought a new fully modular power supply for my PC.
Unfortunately, I did not know that I should not use the old connection cables, because 5V and 12V are reversed.
So i killed my Samsung EVO 850 1TB.
Typ: Samsung EVO 850 1TB
Modell: MZ-75E1T0 2017.11


What i have tested:
The elctric fuse Stef4s (as is found in the forum) was destroyed (burn marks on th chip) and the output is shorted (not zero but 1 Ohm).
So i have desoldered the chip (see Picture) but the output is still shorted (1 Ohm).
So i desoldered also the next to capacitors (I hope that these are capacitors) but the output is still shorted.

Can anyone give me some advices how i can find the short circuit ?
Can anyone told me the values (measured 8,4uF) of the desoldered capacitors?

I read the posts in the forum for samsung ssd, but unfortunately it did not hepl me.

Thanks for help!

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[fzabkar]

Measure the resistance between Ground and each of the Vin and Vout pins of the TPS22966 load switch (14-pin, marking RB966).

viewtopic.php?f=10&t=35276

We need to determine which ICs are connected to the 5V supply. To this end, can you identify the markings on the remaining ICs, including the tiny ones? Can you measure 1 ohm across any of the other capacitors on the PCB?

[Tom33]

Hello, thanks for help!

I measured the resistances (see picture). Both inputs of the IC TPS22966 are short-circuited (0Ohm, 1Ohm).
What you mean with "can you identify the markings on the remaining ICs" sorry my english is maybe not good enough (markings=overprint on the IC?).
I don not know how i can find the short-circuit without try and error (unsolder and resolder parts) method!?

Thank you for helping me!

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[Tom33]

I try to make some pictures with my usb Microscope from the ICs

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[fzabkar]

All the outputs (V1 - V6) of the S2FPS02A02 chip appear to be shorted to ground. This is the main power controller IC. The other power regulator ("PTSI") generates voltage V7. Is the associated test point (capacitor) also shorted to ground?


TPS62130, TPS62130A, Texas Instruments, 3V to 17V, 3A adjustable Step-Down Converter, 3x3 QFN, marking PTSI/PA6I (sometimes marked as GUILL):
http://www.ti.com/lit/ds/symlink/tps62130.pdf

TPS22966, Texas Instruments, 5.5V, 6A, 16-mohm ON-Resistance Dual-Channel Load Switch, marking RB966:
http://www.ti.com/lit/ds/symlink/tps22966.pdf

K4E8E164EB-SGCF, Samsung, LPDDR3 SDRAM, 8Gbit, 1866Mbps, 1.8V/1.2V/1.2V:
https://www.samsung.com/us/samsungsemiconductor/pdfs/PSG_1H_2016.pdf

SN74AUP1G125DCKR, Texas Instruments, Low-Power Single Bus Buffer Gate w/ 3-State Output, 0.8V - 3.6V, marking HMR, SC-70-5:
http://www.ti.com/lit/ds/symlink/sn74aup1g125.pdf

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[Tom33]

I could not really measure V7 with my multimeter (value varies very much), but should not be shorted.

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[fzabkar]

ISTM that the S2FPS02A02 chip is dead. You could confirm this by removing one or more of the inductors (except the V7 inductor) and then retesting for shorts at each of the pads. If the short remains on the IC side of the inductor, but goes away on the capacitor side, then the IC is dead.

[Tom33]

Hello!

You are correct S2FPS02A02 chip is dead.

Can anybody tell me where i can get S2FPS02A02? I cant find it on Mouser, Farnell...

Can anybody confirm me that the capacitors (see my first post) near the Stef4s are 8,5uF?
Can anybody told me the Value of inductors V1 (see picture, post from fzabkar), i destroyed it while soldering it out !

Again thank your al very much for your help, especially fzabkar!
I will give you some feedback if i will get it work again!

[Tom33]

Hello!

You are correct S2FPS02A02 chip is dead.

Can anybody tell me where i can get S2FPS02A02? I cant find it on Mouser, Farnell...

Can anybody confirm me that the capacitors (see my first post) near the Stef4s are 8,5uF?
Can anybody told me the Value of inductors V1 (see picture, post from fzabkar), i destroyed it while soldering it out !

Again thank your al very much for your help, especially fzabkar!
I will give you some feedback if i will get it work again!

[fzabkar]

The capacitors near the STEF4S e-fuse are not critical. They are filter capacitors, so 10uF should be fine. In fact you could bypass the e-fuse with a wire link (by connecting Vin to Vout) and not bother with the capacitors.

I suspect that the S2FPS02A02 is a Samsung device which is application specific and intended for Samsung's own use.

I don't know the value of the inductor. I would guess somewhere between 1 and 10uH ???