Ironwolf Nas 8TB internal SATA - PCB Dead?

[HansMuff]

Hi.

My computer was working over night.
When i woke up the next day my computer was shut down and refused to turn on.

When i disconnect the Seagate Ironwolf the computer starts fine.

Attaching the disc to another computer yields the same result.
Computer doesn't want to turn on...

So i suppose there's a short circuit in the harddisk somewhere?

The hard disk is fairly new (manucfactured Oct 2018), bought 3 months ago.
So i can replace it under warranty that's not the problem...
The problem is i need to rescue the data that's on the disk.

Searching the internet it seems some "TVS-diode" is a common error?
I removed the PCB from the disk, but before i make things worse i'd rather seek for advice.

1) Attached is a photo of the PCB and the parts i identified as TVS-Diodes.
The reading on the chips says "K6U4..."
Is my assumption correct?

2) Attaching my cheap Multimeter and doing a diode test i get the following readings.
Diode 1:
Direction 1: 195 (i believe it's mV)
Direction 2: 1

Diode 2:
Direction 1: 195
Direction 2: 826

So they act differently?
And Diode 2 doesn't "block" in Direction 2?
So i can assume it's faulty?

Thank you for your time!
appreciate any help regarding this

[seed.helper]

i cant understand how seagate is still in business... good luck mate

[fzabkar]

Those are not TVS diodes. Do NOT remove them.

There are two electronic fuses marked "ADTJ" and "AGKJ".

Measure the resistance between +12V and ground, and +5V and ground.

[abolibibelot]

i cant understand how seagate is still in business... good luck mate

That kind of comment is not helping at all. Hard disk drives from all brands sometimes fail, for a variety of reasons. Even if, according to the consensus here, current Seagate designs are less reliable, it does not entail that this particular unit failed because of a design flaw (could be an electric problem of any kind), and that a drive from another brand would have been still working the next morning. The owner (who already did some research and explained the issue in clear terms) is coming here in the hope of getting informed guidance (before attempting something potentially foolish, which many do first), not cryptic allusions to the constructor's bad reputation which won't improve the situation one bit.

[HansMuff]

Those are not TVS diodes. Do NOT remove them.

There are two electronic fuses marked "ADTJ" and "AGKJ".

Measure the resistance between +12V and ground, and +5V and ground.

Apologies if i am doing something stupid.
I am doing this the first time and i am not familiar with all that stuff, but i try to learn

I suppose you want me to do this:

I used the Sata Pinout in the image above.
When i measure any of the 12V Pins with any of the ground pins i don't get a reading. Display stays at the default value "1".
When i measured the resistance between any of the 5V Pins and any of the Ground Pins it says "0.2" (which is the same as when i connect the testing probes directly).
Means i have a short on the 5V line?

Thanks so far.

[fzabkar]

Yes, there is a short at the +5V input to the drive. Now we need to find the shorted component(s).

The 10-pin AGKJ chip is a 5V e-fuse. At its bottom right corner are two unpopulated square pads. Measure the resistance between each pad and ground.

[fzabkar]

Measure the resistances between ground and each of Va and Vb.

MP5000S, Monolithic Power, 12V, 1A - 5A Programmable Current Limit Switch, marking ADT, QFN10:
https://www.monolithicpower.com/DesktopModules/DocumentManage/API/Document/GetDocument?id=1399

MP5010S, Monolithic Power, 5V, 1A - 5A Programmable Current Limit Switch, marking AGK, QFN10:
https://www.monolithicpower.com/DesktopModules/DocumentManage/API/Document/GetDocument?id=1422

[HansMuff]

Measuring the resistance between Ground and Va and Vb yields "1" (OL) (200 Ohm-mode).

Measuring on a higher mode (200k Ohm) yields values around 110 kOhm for Va,
and 199 kOhm for Vb.

[fzabkar]

The 5V e-fuse IC is shorted. I would first check the output of your PSU.

You can choose to replace the fuse, or you can remove it and bridge it, but you must ensure that your PSU is good.

This is the latest link to the datasheet:
https://www.monolithicpower.com/en/documentview/productdocument/index/doc_url/L01QNTAxMFNfcjEuMC5wZGY/prod_id/NDE3/

Edit: One other possible culprit is the capacitor to the left of the IC.

[HansMuff]

Thanks so far.
Need to think about the next steps.

It seems the nearest location for me to order the 5V Fuse is Mouser-Italy (I'm sitting in Croatia).

I have a cheap chinese soldering station similar to:
https://www.aliexpress.com/item/Handskit-2-in-1-Digital-Soldering-Staiton-And-SMD-Rework-8586-110V-220V-Soldering-Station-With/32989272828.html?spm=2114.search0604.3.3.3154593fukLhic&s=p&ws_ab_test=searchweb0_0,searchweb201602_2_10065_10068_319_10059_10884_317_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_10820_10301_10821_10303_537_536,searchweb201603_52,ppcSwitch_0&algo_expid=fd35fe43-4e28-4134-98cf-b1e9654ad845-0&algo_pvid=fd35fe43-4e28-4134-98cf-b1e9654ad845&transAbTest=ae803_3
I believe it can blow up to 400°C.
And my experience comes from watching a couple of PCB repair videos on Youtube.

But this 5V Fuse and it's legs are so small... I am not sure a layman can fix that on it's own...

[HddDonorMarket]

Also you need a microscope.

[fzabkar]

I would cut the ground pin of the e-fuse with flush cutters, and then see if the short circuit persists. If the short is still present, then examine the capacitor. Or you could cut the capacitor first and retest for a short.

If the e-fuse is shorted, then cut all its pins and run a wire from SATA +5V to Va. This will isolate the e-fuse and bypass it.

[abolibibelot]

Perhaps it should be stressed again that if the “bridge” option is chosen, the drive should not be considered “repaired”; if all goes well this quick-and-dirty fix would / should only allow you to make a full backup of the data, then it should no longer be used to store important data. But 8TB is A LOT to backup, the drive will need to be working flawlessly for almost a whole day. You should be absolutely sure that whatever caused the issue in the first place won't happen again during that delicate operation. A good quality PSU is paramount, but if there are severe perturbations with the electrical supply in your area, you should definitely get a UPS (Uninterrupted Power Supply) before proceeding, preferrably a “line-interactive” model (or “on-line” but it's more expensive – just avoid “off-line” designs).