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Samsung T7 no power
http://forum.hddguru.com/viewtopic.php?f=10&t=45909		 Page 1 of 1
Author:  gameboybin [ February 25th, 2026, 4:16 ]
Post subject:  Samsung T7 no power
I have this T7 Samsung SSD. Upon plugging it in. It gives no power at all. What could the problem be?

I have checked all 5V shown like in this post
https://forum.hddguru.com/viewtopic.php?f=10&t=44979&p=314135&hilit=samsung+t7#p314135

all of them shows 0.0V

Maybe it is Type C connector or the Asmedia chip?

On type C pins all shows 0 as well, so no power goes through type C i think.

LED light not flashing or anything

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Author:  fzabkar [ February 25th, 2026, 12:49 ]
Post subject:  Re: Samsung T7 no power
Check the input and output of ES35.

TPS259535, Texas Instruments, 2.7V - 18 V, 4A, 34-mΩ eFuse With Fast Overvoltage Protection, 5.7V clamp, marking ES35, WSON-8:
https://www.ti.com/lit/gpn/tps2595
Author:  gameboybin [ February 25th, 2026, 21:57 ]
Post subject:  Re: Samsung T7 no power
fzabkar wrote:
Check the input and output of ES35.

TPS259535, Texas Instruments, 2.7V - 18 V, 4A, 34-mΩ eFuse With Fast Overvoltage Protection, 5.7V clamp, marking ES35, WSON-8:
https://www.ti.com/lit/gpn/tps2595


The drive today upon turning on did turn on for a split second then turned off
Here is the heat signature of the drive at that exact moment
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here is what i got on in out of ES35
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Author:  SWM [ February 26th, 2026, 8:33 ]
Post subject:  Re: Samsung T7 no power
fzabkar wrote:
Check the input and output of ES35.

TPS259535, Texas Instruments, 2.7V - 18 V, 4A, 34-mΩ eFuse With Fast Overvoltage Protection, 5.7V clamp, marking ES35, WSON-8:
https://www.ti.com/lit/gpn/tps2595

If you read this and compare it with the measurements - ES35 is dead.
(5.1-2.2)/0.034 = 85,3A! :lol:
Author:  fzabkar [ February 26th, 2026, 9:48 ]
Post subject:  Re: Samsung T7 no power
The five "PD5Q" buck regulators have an undervoltage lockout threshold (VUVLO) of 2.2V. I'm wondering whether one of the loads is drawing too much current and causing the ES25 e-fuse to enter current limiting mode. VUVLO would be the equilibrium point. Above this point, the PD5Q ICs start to draw current. Below this point, those ICs switch off.

I would measure the resistance between pin#5 of ES35 and Ground. I would also measure the resistances between Ground and each of the PD5Q outputs.

TPS62085, Texas Instruments, adjustable 3A Step-Down Converter with DCS-Control and Hiccup Short Circuit Protection, 2x2 HotRod Package, marking PD5Q, 7-pin:

https://www.ti.com/lit/ds/symlink/tps62085.pdf
Author:  SWM [ February 26th, 2026, 12:46 ]
Post subject:  Re: Samsung T7 no power
Frank is the smartest. I didn't see that some indexes can "In this case, the device either stays latched-off or starts an auto retry cycle as explained in the Overtemperature Protection (OTP) section"...
Author:  gameboybin [ February 26th, 2026, 21:29 ]
Post subject:  Re: Samsung T7 no power
fzabkar wrote:
The five "PD5Q" buck regulators have an undervoltage lockout threshold (VUVLO) of 2.2V. I'm wondering whether one of the loads is drawing too much current and causing the ES25 e-fuse to enter current limiting mode. VUVLO would be the equilibrium point. Above this point, the PD5Q ICs start to draw current. Below this point, those ICs switch off.

I would measure the resistance between pin#5 of ES35 and Ground. I would also measure the resistances between Ground and each of the PD5Q outputs.

TPS62085, Texas Instruments, adjustable 3A Step-Down Converter with DCS-Control and Hiccup Short Circuit Protection, 2x2 HotRod Package, marking PD5Q, 7-pin:

https://www.ti.com/lit/ds/symlink/tps62085.pdf


Here are the resistances

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Author:  fzabkar [ February 27th, 2026, 12:20 ]
Post subject:  Re: Samsung T7 no power
I don't understand how you can be seeing 0 ohms at ES35, but it appears that the top left PD5Q converter has a shorted load. Hopefully this is due to a shorted capacitor rather than a major IC.
Author:  gameboybin [ March 4th, 2026, 11:53 ]
Post subject:  Re: Samsung T7 no power
So the problem was the ES35 chip. I swapped it out. And the drive powered on
Author:  fzabkar [ March 4th, 2026, 12:04 ]
Post subject:  Re: Samsung T7 no power
Why were you measuring 0 ohms at the output of the 3.3V regulator? And how is it possible to measure 2.2V at the output of ES35 when the resistance is 0 ohm?
Author:  Hardcore Games [ March 6th, 2026, 12:20 ]
Post subject:  Re: Samsung T7 no power
gameboybin wrote:
So the problem was the ES35 chip. I swapped it out. And the drive powered on


I presume the T7 is now accessible.
Author:  gameboybin [ March 7th, 2026, 11:11 ]
Post subject:  Re: Samsung T7 no power
fzabkar wrote:
Why were you measuring 0 ohms at the output of the 3.3V regulator? And how is it possible to measure 2.2V at the output of ES35 when the resistance is 0 ohm?


So it must be somekind of locking mechanism when power is not stable or something.

After changing the es35. The resistance only came back to es35. All pd5q still off. After 3-4 times plugging and unplugging the drive. Each pd5q came back to normall and the whole drive worked like a charm
Author:  gameboybin [ March 7th, 2026, 11:11 ]
Post subject:  Re: Samsung T7 no power
Hardcore Games wrote:
gameboybin wrote:
So the problem was the ES35 chip. I swapped it out. And the drive powered on


I presume the T7 is now accessible.


Yes. Fully functional. It does have some hiccups when mapping the data out though. But i managed to map the whole drive
Author:  fzabkar [ March 7th, 2026, 12:24 ]
Post subject:  Re: Samsung T7 no power
gameboybin wrote:
After changing the es35. The resistance only came back to es35. All pd5q still off. After 3-4 times plugging and unplugging the drive. Each pd5q came back to normall and the whole drive worked like a charm

I wonder whether there really was anything wrong with ES35. Instead, it could be that there was a shorted capacitor at the output of the PD5Q 3.3V regulator. Repeated plugging and unplugging may have blown open the short.
Author:  Hardcore Games [ March 7th, 2026, 21:27 ]
Post subject:  Re: Samsung T7 no power
I have not run across many fried ES35 chips suggesting they are reasonably reliable. I make redundant copies of data as I assume storage is flakey at best.

One of my old Samsung MZVLB256HAHQ-000L2 is down to 87% with 3949GB written. I now use this old SSD for general backup storage.
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