I ended up giving it 20V for a number of minutes... i've read through a few of the hddguru posts but i cant seem to find my TVS diodes to test/remove. At least they dont have "typical" markings if they are there. My cheap multimeter says no conductivity in the 2 "S" fuses (I measured both directions).
Fell down a rabbit hole and read that i may not have TV diodes? Any advice would be appreciated. The return window has passed for this drive unfortunately.

The IC marked "WS1 + 325" is a dual e-fuse. "AV" is the 12V TVS diode. Check it for shorts. There is no 5V TVS diode.

Replace the two "S" fuses with 4A fuses, then check for the presence of 5V and 12V at the inputs and outputs of the e-fuse.

This is a similar PCB:

https://forum.hddguru.com/viewtopic.php?p=297017#p297017

Also this one:

https://old.reddit.com/r/datarecovery/comments/17viepa/western_digital_14tb_wd140edgz11b2da2_electrical/

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A backup a day keeps DR away.

PTVS12VP1UP, Nexperia, 12V 600W unidirectional TVS diode, marking AV + txx, SOD128:
https://assets.nexperia.com/documents/data-sheet/PTVSXP1UP_SER.pdf

STEF512PUR, STMicroelectronics, dual electronic fuse (eFuse) for 5 V and 12 V rails, current limit 3A on 5V, 4A on 12V, marking W51, QFN10:
https://cz.mouser.com/datasheet/2/389/stef512pur-1850562.pdf

_________________
A backup a day keeps DR away.

You can try this. Done it a billion times. Fix the PCB, pull data, replace the drive. You check with a multi meter which fuse is bad and remove it. In continuity mode if the multimeter doesnt beep on a fuse its bad. If it does its good. Then bridge the connection with some enamle wire or something. Or replace the fuse. For the TSV diodes. If it beeps its bad, if it doesnt beep its good. You can remove and leave the TSV diode removed.


HOWEVER, I must caution. Doing this removes protection from improper voltage and protection. This is a bodge job to get the PCB to work again for recovery purposes only. You fix the drive, pull the data replace it.

Otherwise replace the components with proper ones as stated above.

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Remember, take your time. Be persistent. If you have doubts stop. Check, then proceed again.

"74" diodes are not TSV (sic) diodes. They are Schottky rectifiers and will normally only be damaged by reverse polarity.

I prefer a resistance test rather than a beep test. Beeping doesn't really give you a conclusive result, and it will sometimes point to problems where none exist.

Edit: 74 = Rohm RB160M-40TR

https://www.lcsc.com/datasheet/C123003.pdf

https://assets.lcsc.com/images/lcsc/900x900/20230101_ROHM-Semicon-RB160M-40TR_C123003_front.jpg

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A backup a day keeps DR away.

Ah that is good to know. thank you for the correction!!!!

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Remember, take your time. Be persistent. If you have doubts stop. Check, then proceed again.