Controller Board Failure / Replacement - WD15EACS-11BHUB0 [ Edited ]

[WorkInTandem]

I have a client with a WD15EACS-11BHUB0 with what appears to be a failed controller board. After searching the forum, I found several posts that suggest removing the TVS diode or moving the chip at U12 to a donor contoller board may allow for data retrieval. I have attached pictures of the failed drive and a donor drive I have obtained. I have looked at the failed board and am unsure of which component is the TVS diode. If possible, could someone please point out the component that needs to be removed as well as any tips on how to remove it? If this method does not work, could you please verify that the donor contoller board is a suitable match to move the chip with the DCM to? Any other suggestions would be greatly appreciated as well. Please note, I have experience with soldering (replacing capacitors, DC jacks, etc.), but have never worked with surface level components. Thank you in advance. 

Respectfully,

Michael Davenport

Failed Controller Board

http://i49.tinypic.com/2ym692w.jpg

Failed Controller Board 2

http://i45.tinypic.com/14v4uhe.jpg

Donor Controller Board

http://i49.tinypic.com/29ekgte.jpg

[Alucardx23]

For replacement board knowledge I recommend you to PM fzabkar.

[fzabkar]

See http://www.users.on.net/~fzabkar/HDD/bigcircuitboard_diodes.jpg

BTW, the last Lithium software update broke my access to these forums (and to Seagate's). I can see my PMs, but when I try to reply to them I get an "unexpected exception error".

[WorkInTandem]

Fzabkar,

After removing the diodes at D3 and D4 will I need to bridge the contact points?  Or do I just need to remove them? I appreciate your help!

[fzabkar]

You must NOT replace a TVS diode with a piece of wire. You would effectively be replacing a short circuit with another short circuit. Just leave the diode out, but be sure that your supply is good. You'll have no second chances.

That said, why are you wanting to remove both diodes? Have you actually measured anything? If both diodes are shorted, then I would suspect that your chances of repair will be low.

[HDDRS]

Its not as simple as moving U12 flash rom chip over from failed board to donor (like it would be on some WD boards with external rom). You can see that U12 position on failed board has no chip, that is because adaptive data is embedded into Marvel controller, and is not external. If removing diodes does not solve the problem, there is an option of manual reconstruction of adaptive data from firmware on the disk.

[fzabkar]

HDDRS, look again. :-)

As for manual reconstruction, there are software tools costing less than US$150 that will do this with a single click.

Otherwise the following supplier offers a free PCB "adaptation" service:
http://www.donordrives.com/blog/pcbswapguide
http://www.donordrives.com/hard-drive-pcb-donor-swap-match

[HDDRS]

---

fzabkar wrote:
HDDRS, look again. :-)

As for manual reconstruction, there are software tools costing less than US$150 that will do this with a single click.

Otherwise the following supplier offers a free PCB "adaptation" service:
http://www.donordrives.com/blog/pcbswapguide
http://www.donordrives.com/hard-drive-pcb-donor-swap-match

---

oops. I have no clue how it apeared to be missing to me. Indeed with a U12 chip present this is a walk in the park.