This is an odd case (at least for me).

Client presented a WD40NDZM-11BCXS1 MyPassport drive.
Drive would not spin when pugged into USB cable.
PCB was removed from HDD.
Inspection of USB C port found no visible damage.

We dumped the ROM, unlocked and wrote to SATA PCB.
Blocked MOD 30, did your usual FW backup and encoutered reading errors.

MOD 02 (both copies) were damaged.
MOD190 is ok.

That is not were the issue occurs.
I think there is enough of original MOD02 left to patch it up using a donor (see screenshot).

However this drive is SEDv2 and I can read sectors with donor board, but as expected content is encrypted.
A visual inspection of the original USB C PCB shows no visible damage and there are no visible shorts.

I have included a picture of the non-working 2060-810033 PCB and a working 2060-810033 PCB.
The only difference I can see (voltage wise) is the appearance of 3V and 17V.

I was wondering if anyone can suggest how to further this without a MCU move.

Thanks.

resistance at 3V on good board: 4.03K
resistance at 3V on bad board: 3.90K

i dont' see any meaningful difference in resistances at 17V points (~300).

fzabkar, at the risk of sounding like an idiot, would you think the boost rail is missing? I can't seem to find an enable line. or maybe I am off track.

The two test points which you have measured as 17V are probably +17V and -17V. If you look closely, the two diodes are reversed biased with respect to each other. I suspect that these supplies have something to do with the piezo-transducer on the headstack. My understanding is that the motor controller switches these supplies, and the preamp negative supply, on and off under command from the MCU. The default state is off, so this would suggest that the MCU and motor controller are not communicating. I think you can simulate the same scenario by shorting appropriate pins of the ROM (to prevent the ROM code from loading).

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A backup a day keeps DR away.

Thank you.

You are correct, it's -17 and +17v.

Assuming this path is correct, would you assume this is a MCU issue or a motor IC issue? Is there any further testing you could suggest that would provide any other insight?

Only reason I ask is I would rather move a motor IC than an MCU.

Can you check whether the crystal is oscillating?

Is 1.8V present at ROM Vcc? You're only showing 0.9V (Vcore?).

Do the +/-17V supplies come up briefly after power on and then switch off?

Does the preamp have a negative rail, and does this come up briefly after power on and then switch off?

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A backup a day keeps DR away.

I'll find out, and thank you.

I'll be back in the office on Monday (or maybe Sunday). You're likely 18 hours ahead of me.

The board is at our lab and I'm off tomorrow.

A WD SES Controller (USB) does appear in device manager; from experience this is not the case when the ROM is not powered (1.8v) - so something is being loaded; likely the USB bridge. Further the MCU does get warm (normal temp when compared to the working donor). From memory, I never see 17V (either side). But I'll double check my work.

I wonder if some 2.5" drives have a -3V supply for the preamp. That could be the supply at the capacitor at the bottom left corner of the motor controller (did you really measure +3V?). There is an inductor immediately to the right of it. I suspect that a diode connects these two components, and I suspect that this diode is integrated within the IC. If this supply comes up and then shuts off, that would suggest that the MCU is not brain dead.

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A backup a day keeps DR away.

Not ghosting you bud; just a crazy Monday.
Answers to your questions tomorrow - thanks.

I have seen a boat load of these USB hard disks sold under the WD passport and so many have failed. I use SATA and M.2 NVMe devices but I found my old EIDE disk in a USB enclosure still comes alive.

AFAIK the WD disks are self encrypting forcing users to plink down to WD to fix the problem.

The USB nature of the disk logic board muddies efforts to see if the diodes and caps are working. USB-C power delivery has to be handled but the pics are not clear enough to identify the power lines. I need to see both sides of the board in high resolution.

Tools need a voltage tester and a possibly a voltage injector. A heat gun is pointless so a small soldering iron will be needed to swap parts.

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Orico DS500C3-US-BK 5-disk 3.5" SATA, iTGZ 4x M.2 2280 Thunderbolt enclosure NVMe/SATA, etc. etc.

MCU / Motor IC are BGA. You're an idiot, check your matrix.