Barracuda XT, Barracuda, Barracuda Green, DiamondMax and other desktop SATA and IDE drives

[fzabkar]

I've seen similar problems at the HDD Guru forums. The data recovery experts usually suggest that the spindle motor may be seized due to bearing damage.

Here are some sound samples from failed drives:

http://datacent.com/hard_drive_sounds.php

http://web.archive.org/web/20051016010750/http://www.hitachigst.com/hddt/knowtree.nsf/cffe836ed7c12018862565b000530c74/4b1a62a50f405d0d86256756006e340c?OpenDocument

[Guido Hermans]

Hi fzabkar,

I've listened to all the sounds, but none sounds familiar... :-(

It is a recurring low *bzz*.

A colleague of mine has a Barracuda at home. I'll try to switch the circuit boards (if they're the same).

Is the spindle motor repairable?

[fzabkar]

According to HDD Guru, a motor swap is a *very* expensive job. :-(

[littlebro]

Fzabkar, could you help me identify my TVS if I upload a pic?  The disks don't spin and I get a nice order when I plug a molex into it.  I've searched the web for pics for my particular model (Seagate Barracuda IDE drive Model # ST3120026A) but no luck.  I've used a multimeter on a couple of circuits and I get no response in two of them.

Any help would be greatly appreciated.  

[fzabkar]

littlebro, please go ahead and upload your photos.

However, if this is your board ...

http://longdata.ru/images/Seagate/ST3120026A_PCB.jpg

... then the BUX part in the top RH corner is your 12V TVS diode, and the QE part is your 5V diode.

FYI, the following article may help you identify the components:

http://hddscan.com/doc/HDD_from_inside.html

What do you mean by "nice order"?

BTW you can search for images using Google as follows:

http://images.google.com/images?q=ST3120026A+board+OR+pcb&btnG=Search&start=0&imgtbs=t&imgtype=photo

Message Edited by fzabkar on 05-02-2010 06:02 AM

[bluewards]

Hi fzabkar, I have the same PCB as Jim Taylor (100512588 REV A). The smaller TVS diode (i'm assuming it's the 5V diode) on my PCB is burnt. Do you know where can I get the original TVS diode from? The label on it says "ON QA R838". I tried searching on Digikey but to no avail. Thanks fzabkar.

[fzabkar]

The diode is manufactured by ON Semicoductor (ON), and its manufacture date is week 38 of 2008 (838). I don't recognise the QA marking code, but perhaps it is a special order for Seagate.

In any case, you should be able to replace it with an SMAJ5.0A (5V working voltage, 400W, unidirectional).

FWIW, here are my scratchpad style notes:
http://www.users.on.net/~fzabkar/HDD/TVS_diodes.txt

[fzabkar]

Bluewards, are you sure you are looking at a TVS diode and not a Schottky flywheel diode? The latter is a critical component of an onboard regulator. It cannot be substituted with a TVS diode.

Can you upload a photo of the damaged area?

[bluewards]

Hi fzabkar, i'm not sure whether it's a TVS diode or a Schottky flywheel diode. Could you please help? Below are the photos of the PCB. thanks for helping out xD

[fzabkar]

bluewards, the circled part is the 5V TVS diode.