Overvolted external hdd, removed TVS diodes, no change

[idoneeffedup]

Hey, I have a Seagate external hard drive. 3TB. Model ST3000DM001.

I absentmindedly plugged my laptop power cord into it and smelled burning after a few seconds. It was inoperable after that, just a fast blinking light. After plenty of internet research this seemed like an open and shut case of burned TVS diode. I opened it up and cut out the 12V diode (labeled KVP,62A,M). I reassembled and plugged it in, and it acted exactly the same as before. I figured maybe the 5V TVS diode was fried too, so I clipped that on next (AE,51A,M). That still didn't fix it.

What gives? Up to now, I have been reinserting it into the external HDD enclosure and using the correct power cable. Is it possible that anything in the case could be compromised? Is it worth dropping it into my pc and wiring it up like an internal HDD? This makes me nervous, as it's my only PC and I don't want to risk anything. What are the reasonable next steps here? Thanks-

[prasadsv]

Check 0 ohm resisters near power connector 5V

[lcoughey]

Be careful...you don't want the ROM chip to get damaged, otherwise you are looking at a very expensive recovery, if recoverable at all.

[idoneeffedup]

Check 0 ohm resisters near power connector 5V

Thanks prasadsv. I'm not sure how to process the test results. I tested them with a multimeter on the 200 ohm setting and they seem to be giving me the same result they do when I put the leads together to test (that is, 0.1-0.5).

[fzabkar]

Which PCB do you have? Could we see a detailed photo of the component side? I suspect that one of the switchmode regulator ICs may have been damaged.

[JGAN]

Did you test to see if you have a short before and after?

[scratchy]

Check 0 ohm in continuity mode on your meter. If you don't get continuity the resistor is shot.

[fzabkar]

Could we see the USB-SATA bridge PCB as well? The OP didn't specify the source of the burning smell. I know that some Seagate enclosures use switching transistors for the +5V/+12V SATA power supplies. It would be advisable to check whether the correct voltages appear at the SATA power outputs of the bridge board.

BTW, even if the drive were functional, its file system would not be visible to the OS when installed internally. This is because Seagate's external enclosures are configured with a sector size of 4KB. When the drive is removed from such an enclosure, its native 512B sector size is exposed. This results in a 4Kn file system on a 512e physical drive.

[idoneeffedup]

I've attached requested pics.

I have to be honest, I'm in over my head here. I don't really know what I'm doing, and the only reason I've come this far is because I can't spend 500+ dollars to send this for recovery, my wife might actually kill me for losing thousands of photos of my kids, and several sources said that the problem could be fixed by simply clipping a few diodes.

The point is, I'll try any solution that doesn't require technical skills/equipment and doesn't risk further damaging the drive. If that sort of solution isn't available, I guess I'll have to save some $$ and send it off for recovery when I can. Any input is greatly appreciated.

[rogfanther]

As you used the wrong psu, the first part to fail should be the usb board, before the disk one. That means, probably you wouldn´t need to mess with the TVS diodes in the disk.

First, you need to eliminate some doubts. So, you will need to connect the disk to a computer, directly ( SATA ) and see if it is at least detected.

If it is detected, you will need another usb board, That is easier than fixing the disk boards in the case of heads being damaged.

But your USB board is burned, around Q1 ( at the corner, near the sata connector ) . Probably that is your problem.

Else, it would be recommended you send the hard disk to someone with more experience, to avoid risking your data.

[fzabkar]

AFAICT, transistor Q3 switches the +5V supply while Q2 and Q1 switch the +12V.

I believe there is a very good chance that the drive is OK -- it appears that the 12V TVS diode protected the HDD by going short circuit. Consequently this short appears to have destroyed Q1 (and possibly Q2). The fact that the zero-ohm resistors are OK would suggest that the overload was not too severe.

Assuming that the rest of the USB-SATA bridge PCB is OK, then there is a simple solution involving one or two wire links. Basically all that would be required would be to bypass both transistor switches.

Start by removing Q1. You can do this by snipping its pins with flush cutters.

Then solder a wire between the +12Vin pin of Q1 and the +12Vout capacitors (or the C76 solder pad above them, or the +12V pin at the SATA connector).

Run a wire from the +5V capacitors to the +5Vout pin of Q3 (or the +5V pin at the SATA connector).

Now power up the bridge board on its own, connect its USB cable to your PC, and measure the 5V and 12V pins at the SATA connector. If they are OK, then you should be good to go, provided that your HDD is OK.

If you are concerned about your HDD's PCB, you can buy a replacement, including firmware transfer, for US$50. It will most probably be OK, though.

Edit: I suspect that the +12V switching arrangement may be similar to the following:
http://www.users.on.net/~fzabkar/HDD/WD ... Switch.txt

Attachments

[rogfanther]

Frank, from what he wrote, he didn´t measure the TVS diode from the HD, he just read somewhere about other cases and removed it . Or do you mean a TVS in the usb board ?

As the OP himself states he doesn´t have much knowledge in electronics, probably an easier and safer way for him would be to buy another usb board and try it with his hard disk. Installing the jumper wires, for someone not used to this kind of work, could end up in a worse situation where the un-TVSed drive would end up overvoltaged for good.

[lcoughey]

There is no reason that this type of recovery should cost more than $500, let alone $500. At the very least, seek the service of a company who will transfer the ROM to a new working PCB for about $50.

[fzabkar]

A competent DIY-er should be able to recover the data for $0. Only 1 or 2 wire links are needed to repair the bridge PCB.

Otherwise the OP can install the drive inside his PC and recover the data with a 4Kn aware tool such as DMDE (US$20).

http://dmde.com/

In the unlikely event that the HDD PCB is not serviceable, the following company will provide a replacement PCB plus firmware transfer for US$50:

http://www.hdd-parts.com/

@rogfanther, I'm aware that the OP did not state that he tested the TVS diodes. However, the nature of the damage to Q3 suggests that the 12V TVS diode was shorted by the overvoltage from the 19V (?) laptop adapter. This transistor would be rated well above 19V, probably 30V or 40V, so an overvoltage, per se, would not have been responsible for its failure. In other words, Q3 was killed by the TVS diode, not by the adapter.

Assuming that the the JMicron bridge IC (JMS577) is powered by the onboard 5V regulator (U4) rather than the USB port, and since the bridge's LED is flashing, this means that the 5V supply was not damaged. This in turn suggests that the HDD's 5V TVS diode would have been OK.

For the benefit of the wider audience ...

JMS577, JMicron, USB3.0 to SATA III enhanced controller

FR9886D, fitipower, 4.5V - 23Vin, 2.5A, 340KHz Synchronous Step-Down DC/DC Converter:
www.fitipower.com/file/image/Image/pdf/ ... N-2012.pdf

GD25D05BT, GigaDevice, SPI serial flash memory, 512Kbit, 2.7V - 3.6V, SOP8:
http://www.gigadevice.com/product/downl ... cale=en_US

[fzabkar]

Typical bridge PCB layout

Code:

                             dual MOSFET switch (WD)
                             or discrete transistors
                                (Seagate)
                                .---------.           .--------.
                                |    _/   |       +12V|        |
   +12V  o----------+--------------o/  o------------->|        |
                    |           |         |           | SATA   |
               .----'----.      |    _/   |           | Power  |
         o     | +5V reg |---+-----o/. o------------->|        |
         |     '---------'   |  |    |    |        +5V|        |
        ===                  |  '----|----'           |        |
        GND          +-------+       |HDD Power       |        |
                     |       |       | On/Off         |        |
                 .---'--. .--'---.   | control        |        |
     switchmode  |Vcore | | Vio  |   |                |  HDD   |
     regulators  '---.--' '--.---'   |                |        |
                     |       |       |                |        |
                     |       |       |                |        |
    .--. USB 2.0 .---'-------'---.   |                |        |
    |  |<------->|               |---+                |        |
    |  |         |   USB-SATA    |      SATA Tx       |        |
    |  |<--------|   Bridge IC   |------------------->| SATA   |
    |  |-------->|               |                    | data   |
    '--' USB 3.0 |               |<-------------------|        |
                 '-.-----.-----.-'      SATA Rx       |        |
        VCC        |     |     |                      '--------'
         +         |     |     |       .----.
         |         |     |     |       |    |
        .-.        |     |     +-------|    | EEPROM/flash
        | |        |     |             |    |(bridge firmware)
     R  | |        |    .-.            '----'
        '-'        |    | | R
         |         |    | |              R
         +---------+    '-'             ___       LED
         |               |        |----|___|------|<-----o VCC
         |               |        |             Error,
       | o               |      |/              Activity
     |=|>  Pushbutton    +------|  Q
       | o   Switch             |>
         |                        |
         |                        |
        ===                      ===
        GND                      GND

[pepe]

Amazing sketch

[fzabkar]

AACircuit (ASCII Art Circuits):
https://josoansi.de/
https://josoansi.de/ascii-circuits.php

Examples:
https://josoansi.de/ascii-circuits.txt

[Amarbir[CDR-Labs]]

Typical bridge PCB layout

Code:

                             dual MOSFET switch (WD)
                             or discrete transistors
                                (Seagate)
                                .---------.           .--------.
                                |    _/   |       +12V|        |
   +12V  o----------+--------------o/  o------------->|        |
                    |           |         |           | SATA   |
               .----'----.      |    _/   |           | Power  |
         o     | +5V reg |---+-----o/. o------------->|        |
         |     '---------'   |  |    |    |        +5V|        |
        ===                  |  '----|----'           |        |
        GND          +-------+       |HDD Power       |        |
                     |       |       | On/Off         |        |
                 .---'--. .--'---.   | control        |        |
     switchmode  |Vcore | | Vio  |   |                |  HDD   |
     regulators  '---.--' '--.---'   |                |        |
                     |       |       |                |        |
                     |       |       |                |        |
    .--. USB 2.0 .---'-------'---.   |                |        |
    |  |<------->|               |---+                |        |
    |  |         |   USB-SATA    |      SATA Tx       |        |
    |  |<--------|   Bridge IC   |------------------->| SATA   |
    |  |-------->|               |                    | data   |
    '--' USB 3.0 |               |<-------------------|        |
                 '-.-----.-----.-'      SATA Rx       |        |
        VCC        |     |     |                      '--------'
         +         |     |     |       .----.
         |         |     |     |       |    |
        .-.        |     |     +-------|    | EEPROM/flash
        | |        |     |             |    |(bridge firmware)
     R  | |        |    .-.            '----'
        '-'        |    | | R
         |         |    | |              R
         +---------+    '-'             ___       LED
         |               |        |----|___|------|<-----o VCC
         |               |        |             Error,
       | o               |      |/              Activity
     |=|>  Pushbutton    +------|  Q
       | o   Switch             |>
         |                        |
         |                        |
        ===                      ===
        GND                      GND

Amazing ,
Amazing sketch there frank ,Very clear and good work

[RolandJS]

As a DR duffer, an absolute beginner just at the software level, I ask:
If there are no backups of the data on this drive, would the OP be much better off sending that device to a DR company/specialist right away? I keep reading on The 'Net that most DIY attempts, very likely, very often, results in much more DR time and effort, much more DR expense, and less chances of successful and usable data recovery?

[fzabkar]

As a DR duffer, an absolute beginner just at the software level, I ask:
If there are no backups of the data on this drive, would the OP be much better off sending that device to a DR company/specialist right away? I keep reading on The 'Net that most DIY attempts, very likely, very often, results in much more DR time and effort, much more DR expense, and less chances of successful and usable data recovery?

The problem is extremely trivial. If the OP cannot do otherwise, then he can buy a replacement bridge PCB plus a replacement HDD PCB with firmware transfer.