Unbricking a Seagate Barracuda

Recently, one of my hard disks ‘disappeared’ from my computer – it was not being detected in the BIOS. It turned out that this was a known issue with my drive, and one for which Seagate had released a firmware update.

Unfortunately, the update could only be applied to functioning drives. Seagate will apply the fix to bricked drives for free, but I was reluctant to send my drive to them because I didn’t want to give strangers access to my personal information. I wanted to do it myself.

After a bit of a search I came across this enormous thread. The first post has changed quite a bit since I first saw it – it initially contained a lot of true and false information, and the same followed in the rest of the thread. I spent some time cross-referencing the various opinions and experiences, and finally managed to unbrick my drive.

I had intended to provide a how-to here but I have since discovered that someone has already done it. What I did was pretty much the same as the author of that guide, except that I used a USB cable instead of a serial adapter.

I found myself a Nokia data cable (DKU-5) and cut off the phone end. With the help of a multimeter I determined which wires were used for transmit, receive and ground, and connected them to some wires I cut off an internal CD-ROM cable. These wires were attached to jumper pins, which I was able to slot into the hard disk. The USB end plugged into my computer, and I was able to connect to my hard disk via putty.

Apart from that, the steps I followed are identical to the guide above. I don’t recommend that people do it – if you have this problem and aren’t wearing a tinfoil hat, I reckon you ought to send it back to Seagate and safely recover your data.

Here are a few photos that I took during the operation.

42 thoughts on “Unbricking a Seagate Barracuda

  1. Stuart: not ssh, just a very basic terminal running on the PCB. There’s no established connection, just sending and receiving of data.

    Jonathan: You can still connect to a drive and have a look around, even if you don’t need to perform a fix :)

    The highlight for me was getting the USB cable working. I installed the Nokia cable’s usual drivers and (after the snip) connected the RX and TX wires to each other. I connected putty to COM8 (discovered via Device Manager), turned local echo off, and started typing. Seeing my characters appear on the screen was fantastic.

  2. The most stressful part was re-attaching the PCB while it was powered and connected to the computer. I used u-tac to hold the screws to the screwdriver so that I didn’t drop them somewhere sensitive and short something.

  3. Hi Mathew,

    I am trying to do this DIY as well but am running into some problems which hopefully u can help.

    I snip off the usb connected to a old USB port. I found the 4 wries there, tx, rx, gnd and pwr cable. The Green and White seems to be the tx and rx.

    So the next steps followed :

    1. Create a loopback between the tx and rx wires.
    2. Connext the USB end of the cable into the PC
    3. Start hyperterminal.

    The problem starts from 3. I was not able to tell which COM port the cable was using. It was not shown in device manager as well (WinXP). Hyperterminal only shows com1 which was the serial port. Any idea how i could fixed it?

    I tried putty as well but it doesnt work. Is the setup so simple (barred the harddisk and cardstock and screwing in etc). Connect the USB end into the PC and start the terminal program?

    Thanks for your help

  4. Hi TW,

    Are you using a DKU-5 (or similar) USB cable? The required cable isn’t a regular USB cable but one containing the circuitry to create a serial signal. I used an old Nokia phone cable.

    When you insert the correct cable, Windows should detect it and ask for drivers. I was lucky – I bought mine from eBay and it didn’t come with drivers, but Vista detected and installed the correct ones (after automatically searching online). The cable then appeared as “USB-Serial Controller” in Device Manager, and listed the COM port number.

    As for your final question – yes, it was that simple for me. You’ll need to check that the cable is working correctly via the loopback method before you attach it to the hard disk, though. It sounds to me that you don’t have the correct cable, or the correct drivers haven’t been installed.

    Good luck!

  5. In the link you posted there’s this “Powering the RS232-to-TTL Adapter”. Do I need to do that using the dku-5 cable? I also have a dku-5 cable that i could use, but don’t have a multimeter…could you show which color of the wire goes to the jumper pins? I hope you could post a step by step complete instructions to follow because your version is easier to follow.

    Good job!

  6. itoT: I don’t know – I’m not sure what functionality that cable has.

    kavrron: If you went the RS232 route you’d have to add power because none is supplied, but USB provides its own power so I didn’t have to. I can’t help you out with wire colours, I’m afraid – it seems that any given USB cable uses different colours so there’s no way to be sure without testing it.

  7. ive looked at the pics and it seams to have a gnd attached to it but you do not say in your guide if u need to connect this, can you please let me know

  8. michael: I attached the gnd without even thinking whether or not it was a good idea. It could have been disastrous, I have no idea. I have noticed that some people on the web have connected it and some haven’t, and I’m not knowledgeable enough to give you a definitive answer.

    It’s gaps like these that prevents me from putting up a complete tutorial. I don’t feel comfortable doing that when I’m not 100% about the process, so I’ve just documented my experience and if that assists people, great.

  9. Hi, I’m trying this with an oem dku-5 cable. It’s got 5 wires in it and 6 pins (with no missing pins) on the phone connector. How did you know which pins are Gnd, Rv, Tx? If I # the pins from the closest end, the wires are connected to 1, 2, 4, 5, 6. I’m comparing against http://www.lathey.co.uk/guides/NokiaPOP-PortPinout.pdf

    Also, I’m not getting any voltage when I tried a volt meter across all 5 wires (in all combinations of pairs).

    I’ve got the Nokia driver loaded – and a COM port appears, so that seems fine.

    Any ideas?

  10. Going by your pinout it appears as though 6 is receive, 7 is transmit, and 8 is ground. There doesn’t seem to be a standard for dku-5 wire colours, so the only way to be sure is to test them.

    I didn’t check for voltage but used Ohms to check for continuity. If you look at the multimeter photo you can see that I’ve switched it to the Ohm side, and by default the value (resistance) is 1. If I were to touch the probes together the resistance should drop to zero (or thereabouts). As you can see in that photo I cut the Nokia end from the cable and separated the wires. I then used this resistance method to check which wire matched which pin.

    It sounds like you have the right cable, so once you’ve found the Rx and Tx wires you should be about to tie them to each other, connect to the COM port (using putty or hyperterminal or similar), and whatever you type on the keyboard should appear on the screen (as the data loops back through the wires). You can then be satisfied that you have the correct wires, and can attach them to your hard drive. Keep in mind that the Rx and Tx needs to be reversed on the drive (because the drive will be receiving what the USB cable is transmitting!)

  11. Hola, muy buen aporte pero mi consulta es si esto lo puedo hacer con un cable USB ERI T237 de un celular sony ericsson.


  12. ‘Yeah but you for got to mention that it only works with the Chinese Nokia (DKU-5) and not the original spent days and many leads before finding this out…..Does not work with original Nokia cables if so how!


  13. Hugh: I did specify that I used a DKU-5 cable. I’ve had one for years for use with my old Nokia phone. I wasn’t aware that it was Chinese or otherwise; I’m in Australia and it’s simply what was available.

    I have no experience doing this with any other cable so I can’t help you. You could try asking your question in the forum thread I linked; it still seems to be active.


  14. Mathew which color are for TX/RX/GRND? I need to unbrick my seagate HD. and I can connect the ground to the USB also so I wont be needing those RS232 – TTL adaptors? Thanks… I really need some answers.

  15. Mark: As I said in an earlier response, there’s no standard for wire colouring so I have no way of knowing which wire is which in your case. You need to test them.

    But yes, if you use a DKU-5 USB cable like I did there’s no need for an RS232 adapter.

  16. Ok so I’ll just have to follow the sequence from pinouts.ru then I can get the TX/RX/GRND cables inside. Thanks a lot.

  17. I know this post is getting old, but after over a year my Seagate finally hit that dreaded 320 mark (or multiple thereof) I only recently found out about this problem when my HD quit working and I searched the net to find a reason.
    Anyways, I have downloaded the firmware update and putty. This leads me to the next step, the connection. My question is, do you think any cell phone data usb cable will work? I have plenty of old cd-rom cables in the basement.

  18. Shawn: Maybe – if you plug a cable into your computer and Windows detects it and creates a new COM port for it (which you’ll see appear in the device manager), you’re halfway there. It would just be a matter of determining the correct Rx and Tx wires, then.

    Jeremy: In theory the data should be fine, because you’re not changing anything on the disk itself but unlocking a simple setting on the logic card. My data was fine, at any rate! Don’t rely on me, though – if you have crucial files to restore it’s probably safer to send it back to Seagate.

  19. Hi Mathew,
    I am trying to unbrick my hdd, but when I connect to Hyperterminal or Putty and enter Ctrl+z my com prompt shows F> and I cannot access level 2. Any ideas? PS. I am using a Nokia Usb to Uart cable model CA-42 with drivers install, alsoo I am only able to communicate at a rate of 9600 instead of 38400.

  20. I have prepared the cable rs232 to TTL and i am going to plug in on the dodgy hdd. I am using a homemade pcb though. tested like you are describing above and works fine.Today afternoon I ‘ll tell you the result. my hard drive is 7200.11 and 500Gb, and is not recognized by the pc bios.

  21. hmmm, I have taken my seagate out of its external drive cover, so Im guessing thats voided the warranty, since then I discovered the bricking problem, which Im pretty convinced is the problem, (drive sounds healthy) and I dont think I’m savvy enough to succeed at this procedure.

    You wouldn’t be in Sydney by any chance? I am! :)


  22. Hi, so I read the linked tutorial, and the guy says this only works if bios says bsy, if bios has 0 MB shown you need different instructions.. Any idea what those different instructions are? There is no way to contact the writer of the tutorial, that I could see.

  23. Matt, I have a few questions. I noticed on the alldav site there’s a RS232 to TTL/CMOS converter and a RS232 to TTL converter. Does it matter which one? And can you give me exact names of the wires you used?

  24. Hassiem: No, I have no idea. I was fortunate that it worked for me; I wouldn’t have been able to figure it out if I’d had problems.
    Trev: No, nowhere near Sydney :)
    MC: No, I don’t know anything more than I’ve said, I’m afraid.
    Meiko: I didn’t use that method, so I don’t know. Also, as I’ve said before, I can’t give you names of the wires because they vary from cable to cable. The only way to be sure was to use a multimeter.

    Sorry for the late reply, I’ve been away a while. Not that I helped anyone, anyway!

  25. I followed the procedure above on my bricked 7200.11 with SD15 firmware, and the drive is again working. However, when I attempt to flash the drive with the corrected firmware, it shows up in that process as a ‘ST31000340AS’, instead of the ST3750330AS’ that it really is. Is there something about the process that might have resulted in this situation? Goes without saying that the firmware update did not succeed, and Seagate Tech Support now reports that since I did this repair I have voided the warranty – jeez!

  26. Dan S, and the rest of you, i have better advice, bring your HDD to i356 (A Seagate Company), they flash your drive for free, because of the FirmWare Epic Fail, and it won’t void warranties. I mean, free, and all the mess and work less. So don’t do this and just go to i365, or let your local mail service bring it, wich is also free.

  27. Daniel: That’s the same advice I gave in my original post, which was a “this is what I did”, not a howto.

    “I don’t recommend that people do it – if you have this problem and aren’t wearing a tinfoil hat, send it back to Seagate to safely recover your data.”

    Dan S: I’m sorry to hear that. I don’t know why that would happen.

  28. my hdd is showing the problem

    MODEL : ST3750330NS

    visiting card inserted motor contacts disable

    F3 T> ^A

    Controller FW Rev: 12061642, CustomerRel: SN04, Changelist: 00052376, ProdType:
    MS01.SDN1, Date: 12/06/2007, Time: 164517, UserId: 00011250
    Servo FW Rev: B0FA
    RAP Format Rev: 0092, Contents Rev: 15 05 00 08

    F3 2>Z

    Spin Down Complete
    Elapsed Time 0.149 msecs

    F3 2>/2

    F3 2>U

    Error 1009 DETSEC 00006008
    Spin Error
    Elapsed Time 29.501 secs
    R/W Status 2 R/W Error 84150180
    F3 2>m0,2,2,,,,,22

    Unable to load Diag Overlay

    F3 2>/1

    F3 1>N1

    Unable to load Diag Overlay

    F3 1>/T

    F3 T>i4,1,22

    Unable to load Diag Overlay

    F3 T>

    need adivce for terminal command,
    this error is repaiable or not,


  29. Thanks, Matt between this and a couple of other posts on this subject you have all given me enough information to do a successful recovery.

    The gotcha for me was the genuine Nokia CA-42 cable I was using needed 3v power so I hooked up the ground (black) to the negative and red (3.3V) to the positive of the cmos battery.

    After that it was just a case of swapping the RX and TX (Blue and white in my case) as the usb end was sealed so i couldnt find out which was which but swapping it is no prob.

    Other resouces used were




    Thanks again

  30. Hi Mathew,
    I have a Seagate HDD with the same problem (it is not discovered from BIOS), and on it I have a lot of information. I’m wondering could I have this information after “unbricking” my HDD or it’ll be formatted.
    Thank you

  31. Veselin: This process should restore your ability to access the information, not format your disk. However, don’t risk important data – send it back to Seagate.

    Doug: No worries, glad it worked for you!

  32. Hello, Mathew and other experts:

    My Seagate hard drive (2 GB, green, Barracude) seems to have the firmware problem, i.e. the hard drive is not recognized by BIOS. I can feel that it spins as normal. There are some posts on the web on restore the hard drive from the busy state to normal state.

    First, I remove the star shape screws of the hard drive PCB. Then, insert a piece of paper on top of the read/write head connector and the PCB board.

    When I connect the hard drive serial RS-232 port to a USB-Serial adapter at a PC USB port, connect the SATA hard drive power cable to a PC and the hard drive, it shows in my PC putty terminal window (38400 baud, 8/1 bit, no parity, no flow control):

    Boot 0x40M
    Spin Up

    then, I feel the hard drive stops spinning. There is no communication any more. Of course, it does not respond to Ctrl+Z command. I suspect that it goes to a protection mode from other on-line posts. There is only one procedure I am not sure. It is to insert a piece of paper between data SMT connector and PCB. Before un-assemble PCB for the paper inserting, hard drive motor spins forever after power it up. Could you tell me what is wrong?

    Thanks a lot

    rxjwg98 at gmail dot com

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