Hello,

I have an external USB HDD WD7500KMVV-11A27S0.

The drive was plugged into an USB HUB with an external power adapter. The hub
was plugged to a 12V adapter, and not to the original 5V.
The drive does not work anymore, it does not spin.

I understand that in some cases a TVS diode could be removed, and that with a little bit of luck that is the only thing blown. I found only one diode in the PCB, D2, but I'm not certain of this could give me the chance to make the disk run en copy the data.

Does any one knows, had a similar experience?

Thanks in advance.

If data is important , take pro help.
DIY on drives with data is not advised.

In your drive there is no TVS diodes , and hence no easy DIY fix.
There will be a fuse (or similar) on the 5V line which would have failed, but there are chances that some other controllers would have failed too.
You will need proper tools and knowledge to test and identify if that is the case.

Replacing with a similar board after transferring the rom is the next option.

DIY has its risks . Think and decide.

Thank you for your answer. I understand the risks.
It would be nice if I have the data back, but not that much to pay for the recovery.
I probably don't have all the tools, but I can get access to much of what is needed so far I know. (not a clean room ).

I take this as a side project and an opportunity to learn more about hard disks and data recovery, if I recover the data,
it would be great, but if I don't, no big loss.

Hi Spidit,

The U14 is a SST 25VF010A.

For what I've read, I understand that the chip that should be moved should be in U12, but in this PCB U12 is vacant. That means that the "adaptive data" is embedded in de Marvell chip 88i8946-TFJ2. So, the data should be cloned, and then recompiled in the new PCB.


I've a donor drive which is exactly the same, but with a different DCM.
Original DCM HBBV2HNB
Donor DCM: HHCV2HBB

In that PCB, U12 is also vacant and U14 is a Winbond 25X20ALNIG.

I suspect that the Motor controller may be damaged. Last time that this PCB was plugged, I could felt that the PCB was very hot where this IC (SH6601AD) is located. There is no evident (burned) damage. I have to test it.

If the ROM is actually embedded in 88i8946-TFJ2, and it is damaged, I guess that this will be a lot more challenging. Even swapping platters would not make it work. Am I correct?

Why would changing platters fix a problem with the rom? That's like changing a lightbulb when switch is busted.

If you swap platters then you still lose your data, the platters are where it's all stored.

I suggest you save up a dollar a day. And by next year this time you'll be able to get a pro to look at it, and if it's a simple job, done for that price.

_________________
On a clear disk you can seek forever.

Hi Keatah,

Thank you for your post.

Swapping platters would not fix a problem with the ROM. I meant, as a last resource in the case that ROM storage is damaged, possibly other controllers and pre-amp are killed, even swapping the platters to the donor drive would be useless if you don't have the unique data from the original ROM. I suppose that then the only way is to reconstruct the ROM data, which is not impossible but takes a lot of work.

As I said earlier, I'm not really considering sending the drive to a DR specialist, but I will consider your suggestion.

Forensics labs have unique methods of getting data off the chips. Even if there are cracks in the silicon itself which have busted part of the circuitry or wirebonding. Incredible stuff!

_________________
On a clear disk you can seek forever.

If you have the proper tools and experience , change the VCM IC (SH6601AD) at U1 and try.(as the data is not that critical to you)

What if the PA is fried... And good luck when removing the chip with DIY methods...

Hi Sathyan,

Soldering / desoldering would not be a problem. BlackST's suggestion that the preamp maybe damaged is actually possible, in that case I will need to swap the HSA, from the donor drive that I assume is compatible. If I come to that point, I suppose that probably other PCB components would be damaged too.

There are chances that what BlackST suggested can be possible, fried preamp.(along with other components in the pcb)
But as you don't want to take pro help and data being not that critical, the only other option as DIY (with proper tools and experience) would be to swap the VCM and hope other things survived the power surge ( unlikely)

But if you are thinking of swapping the HSA , its not that easy, sorry.
Definitely not DIY even with proper tools(without prior experience).
Before opening the drive , have to make sure the problem is internal, and also have to rectify the faults in the pcb.

There is a point , beyond which DIY is not possible.
So , if you value your data, save it till you have the resources for recovery later.

So if thats the case then what happended when you just exchanged the pcb?
I'm sure you have already tried so what was the outcome?

Hi Dick,

That is indeed the first I did.
No spinnig at all, the led was blinking, the PC and the Macbook did not recognize nothing at all.

That is why I suspect that there is more damage than a few fried components in the PCB.