I got a 4TB My Passport Drive from WD. That doesn't show any sign of life on the PCB. The USB connector is fine. I soldered a Sata connection to test the PCB. There is 0 amps drawn on 5v rail

I wanted to know if someone could provide me with crucial measuring points, components and voltage rails of this PCB
Many Thanks!

measure the 000 ohm resistor in between the 2 connectors with a multimeter, diode/continuity check mode. it should beep.

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Adatmentés - Data recovery

It probably will beep. The usual fault is dry solder joints at each end of the resistor, not the resistor itself. Reflowing the solder should fix the problem.

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A backup a day keeps DR away.

Small question guys. In case the PCB is badly damaged. What chips you need to swap to the donor in order for the PCB to work? I heard that with these new SMR drives not only BIOS need to be swapped?!

Some of these PCBs have a key in the MCU, so that means you need to transfer the MCU as well as the ROM.

To answer your original question, here are the test points:

https://web.archive.org/web/20210614193827/http://www.users.on.net/~fzabkar/HDD/WD40NDZW_TVS_diode_fuse.jpg
https://web.archive.org/web/20230730202427/http://www.users.on.net/~fzabkar/HDD/WD40NDZW_bridge_Vcore.jpg
https://web.archive.org/web/20220113231223/http://www.users.on.net/~fzabkar/HDD/WD40NDZW_regs.jpg

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A backup a day keeps DR away.

Okay. So i measured all the points in 3 pictures as well as the 0 Ohm resistor. all of them seems fine
I measured across 1 donner working board.

There are 3 things

1st, i tested heat spot from the donor board vs the broken board. It seems missing the heat from the SATA controller. Means the voltage is not getting there

2nd, upon turning the broken PCB board on the LED light lights up but very DIM. Not bright as the working one. The PC3000 showing jumping amps between 16-20 on 5v and the PCB stayed BSY

3rd, i did found a W1P 87 transistor that shows different measurements i guess it might be the culprit or maybe the SATA controller itself. I will try swapping them over. Hope for the best

If anyone have any ideas please let me know
Many thanks!!!

New findings. So apparently the LED is fried that's why the Transistor has different measurements. Swapped the LED now shines bright

I found a broken trace at the MCU that maybe the cause of this. Trying to solder those points but haven't got luck cause the points are small

A broken solder joint wont be the source of a short - nice catch though.

If you're struggling with soldering and can't justify the JVC kit (who can) an Axium T115 station is cheap enough and will have no problems at that scale with decent optics.

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Data Recovery Services in the UK.
https://www.usbrecovery.co.uk/

- So I measured all components but found no short on the board. Does it mean that the only thing can go bad is the SATA Controller chip???

- I will find a way to solder that. Just not at the time when i was writing the comment just a little bit of struggling

A little off on the scale there. 150-200mA could be standard drawn on the board, check with a donor. Assuming you've reflowed that troublesome resistor that sort of pattern is usually an IC failing to start and whilst your thermal camera show "hot spot" these aren't hot enough not to be normal operation. Given all the major IC's appear to be getting power I'd start looking at enable signals but check your voltage rails anyway. Also look at the pcb on edge - is it flat ?

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Data Recovery Services in the UK.
https://www.usbrecovery.co.uk/

Just FYI, a transistor is often used to drive a device whose current requirements are greater than that which can supplied by the MCU or bridge.

MCU I/O pin --> transistor --> LED

http://markingcodes.com/search/c/W1P

PMBT2222A, NXP, NPN switching transistor, 40V, 600mA, marking *1P, SOT23:
https://datasheet.lcsc.com/lcsc/1811141239_Nexperia-PMBT2222A-215_C23869.pdf

Have you dumped the MCU ROM? Perhaps it is corrupt? I have written a tool to check its consistency.

BTW, did you measure the voltage on that MCU pin to confirm that the trace is indeed open?

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A backup a day keeps DR away.

I have not. How can i get hold of your tool to check its consistency???

Apparently there are also problems with the ROM chip above
I thought this ROM is locked and need unlocking procedure with PC3000 but apparently After pogoing, reading the rom out after verifying with pogo sticks many times. The ROM has a lot of errors. I'm supper blind now. Don't know where to go from here, or what causing all of this

I am sending the ROM hopefully some one could check it out for me

I am sending the ROM hopefully some one could check it out for me

https://drive.google.com/file/d/1T0h6mM ... drive_link

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A backup a day keeps DR away.

Can you take a look for me. Or tell me how to use that .exe program???

The tool runs from the command line in a Windows DOS box. Just type the name of the file to see the embedded usage instructions.

As for your ROM dump, it has hundreds of errors.

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A backup a day keeps DR away.

Yeah. I found out that the ROM is broken. Are there anyway that i can fix this?? I believe that each drive has unique ROM isn't it?? So this case is unsolvable??

Take several ROM dumps and upload them. If you have a good donor ROM, either USB or SATA, could you upload that as well?

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A backup a day keeps DR away.