Two fired seagate HDD

[PenKnight]

Hello everyone

I'm looking to try and recover some data off these hard drives. Both got over volted and no longer power on, the drives remain cold and do not spin. I have detached the PCB boards for inspection and pictures can be found here

http://www.flickr.com/photos/64388554@N ... 033335830/

I'm about to test them tomorrow with a multimeter but I would like to know a couple of things first.

When I test each TVS, should i get overload errors for both direction?
What would be a sensible upper value that i should detect if they were working?

For hard drive 1, I pretty confident that the TVS has done there job and the board seems to be in good condition. Except there is a few black marking on the right hand side ( see the picture set for details). I also can tell you that I heard a nice fizzing sound before it went silent.

For hard drive 2, the inductors are gone. Not too sure what these do/are but what readings should I be observing. Actually, I could find this by testing the non-broken ones lol.
I've read the general fix is to solder on a short piece of wire. This hard drive also has lots of discoloration, I am worried that more than the board has been affected. What else could i look for / test before attempting a repair on the second hard drive.

Just for the record, I've burnt them by using a sata power cable from a modular corsair 750W PSU with a modular Evo blue 650W PSU.

Cheers for any help provided.

[hdd119]

IS Q8 HAVE OUTPUT ?
OR ROM IS OK?

[italianrecovery]

The values for the TVS shoud be 1 in one direction and a low value in the other direction.
For a brief tutorial see this link
http://www.allaboutcircuits.com/vol_3/chpt_3/2.html

[loki]

Diode testing guide

http://www.electrosport.com/technical-r ... -guide.pdf

[fzabkar]

Your drives appear to have sustained an overvoltage on the +5V supply.

On drive #2, the function of the inductors is to filter any high frequency noise on the +5V supply. You will probably find that the 5V TVS diode at the left side of the board is shorted. The fix is to remove the diode, and replace the inductors with wire links.

These photo clips should help you identify the components:
http://www.users.on.net/~fzabkar/HDD/ST ... uctors.jpg
http://www.users.on.net/~fzabkar/HDD/ST ... 5V_TVS.jpg
http://www.users.on.net/~fzabkar/HDD/ST ... 2V_TVS.jpg

On drive #1, you should also test the 5V TVS diode (marking QA).

[PenKnight]

@Hdd119
I am sorry, i do not know what that is and how to determine whether they are in working order

I understand enough to test a diode, was looking for possible outcomes to try and understand what happened. Borrowed a multimeter today and checked the diodes out.
Only the 5V TVS have been shorted and just the two inductors on HDD#2 has been destroyed. Inductors have been tested to short out.
Thank you fzabkar for explain the purpose of those inductors and confirming those TVS diode locations.

I have another query for HDD #1. Looking at the underside, my friend has notice that the shiny metal area is not clean. They are rather dirty and usggested that these could be damaged in some way. Obviosuly, an over volt could have also damaged the component internally but would this sign mean anything significant?

Here are the pictures of the underside of HDD #1.

http://www.flickr.com/photos/64388554@N05/5880300766/
http://www.flickr.com/photos/64388554@N05/5880300496/

[italian-recovery]

Hi,
this type of dirty surfaces is quite common in this type of hard drives, nothing to worry about ..
However if you want you can also gently clean them using a rubber eraser

[fzabkar]

See this thread:
http://community.wdc.com/t5/Desktop/WD- ... td-p/24697

BTW, a possible alternative to scrubbing the contacts with an eraser is to use a cotton bud to apply a metal polish such as Brasso. I haven't used Brasso on HDD PCBS, but it works very well on electrical contacts made from pre-RoHS materials.

[PenKnight]

It's been a while and need help with HDD #2 burnt inductor. Wondering how to connect the 7 8 9 pins to the board, ( the number are in reference to fzabkar pictures, see above post)

http://www.flickr.com/photos/64388554@N ... 033335830/ (Picture of my burnt PCB)

The 7 8 9 pins seem to connected together and distributed to two component. Would A nice blob of solder be good to connect everything up together? (As shown in the picture below)

http://www.flickr.com/photos/64388554@N05/5965719639/

Also, HDD #1 has been recovered. I am very happy at the moment.

[PenKnight]

Update:

Made the big blob and successful recovered the hard drive. I could not find the edit button to change the previous post.