Remove TVS Diode on WD 4TB Black

[gibson]

Inadvertently plugged SATA power cable from Corsair PSU into EVGA PSU and blew 3 drives on that cable. Apparently the pin outs on the cables are different resulting in an over-voltage to the drives. The drives will not spin up and appear to receive no power.

I've spent most of the day researching repair and found some excellent information here so I thought I would post my situation and seek advice before proceeding with repair. I have some data I need to recover from two of the drives. From my research today I feel confident my issue is related to a blown TVS diode. Ideally and assuming this is correct, I would just like to remove the diode, transfer my data and replace the drives. I have a clean power supply ready to go once the drives are operational.

I am not experienced working on electronics so I would really just like to figure out which diode actually needs to be removed and have a local technician do the work for me. I do have a multimeter and can test as needed.

I am attaching a picture of the PCB from one of the drives. The drives are identical. They are WD4004FZWX 4TB Black.

I've contacted a few companies and apparently the PCB for this drive is hard to find. Most places are offering to repair the board rather than replace.

Thanks in advance.

greg

[gibson]

I'm noticing that this PCB doesn't have any of the standard component labels. No D3, D4, R67 etc that I have seen discussed here on other WD PCBs.

[Tomset]

This
HUS726040ALA614
Only with sticker WD

[gibson]

Thanks is there a relatively simple procedure, like removing a failsafe diode, that will restore power to the drive?

greg

[Amarbir[CDR-Labs]]

Thanks is there a relatively simple procedure, like removing a failsafe diode, that will restore power to the drive?

greg

Hi Greg ,
How About Buying a New PCB ,Then Removing 8 Leg ROM Chip From Old Bad Board And Migrating It To New Board And Trying To Power Up The Drive ,If It Clicks Then The Old Board Has Taken The Heads Along With It Also ,Just Removing TVS Diode And Not Having Idea How To Test The Complete Board is a 50% Gamble

[gibson]

Thanks Amarbir - I'd be happy to buy a new board but I am having difficulty sourcing one. I talked to a few companies that advertise PCB repair/replacement, like PCBSolution, Donor Drives and DataPro. Can't find anyone with the board. All have offered to repair.

I am attaching a picture of the backside of the board. There is a picture of the front side of the board in my initial post. If there are any identifying codes that will help me source new boards I am happy to do so.

Thank you for the response.

greg

Attachments

[gibson]

Is it possible to buy another of the same drive, swap the board and move the ROM chip over?

Thanks,

greg

[scratchy]

Is photo of drive's Lid available.

[gibson]

Yes. No problem. Here is the label from both drives.

[inflex]

Measure resistance across the terminals of the components in the red circles for me please.

I've done quite a few TVS repairs, it is simple/quick if it's the fault and you have the right equipment ( decent hot-air station preferred ).

Can you read the numbers/letters off the ST part (horizontal middle one) ?

Attachments

[gibson]

The horizontal component measures .188 in one direction and 1.148 in the other. The number on top is GP 617.

The vertical component measures .189 in one direction and OL in the other. I believe the number is L14 but could be U14 or G14. It's a bit obscured.

Thanks,

greg

[F_ARG]

TVS seems to be ok, can you check fuses?

[gibson]

which are the fuses?

[F_ARG]

Seems that the ones i ve marked in black are fuses, but i can´t tell it for sure (does they have any inscription on it?). The one in yellow is a 0 ohm resistor, you can check it too.

Best!

F

Attachments

Nueva imagen de mapa de bits (2).png (559.31 KiB) Viewed 22503 times

[mr_spokk]

Never seen those...but Pcb label indicates of a Hitachi involvement.
Pcb is here: http://www.ebay.com/itm/PCB-0J43734-BA5 ... 2043208377

[gibson]

I had a hard time testing those fuses and the zero ohm resistor. Had to have my wife hold a magnifier and my probe tips are little large but here's what I got.

On the lower left fuse I got a tone and 0.00. On the middle I got nothing. No tone, just OL on the display. On the zero ohm resistor I got tone and 0.00.

greg

[gibson]

Spock - yes, that's the board thanks!

Still wondering if I can just purchase the same WD drive and use that board as a donor?

Would that work?

Thanks,

greg

[gibson]

I meant to say purchase the same WD HD and use that board as a donor along with a ROM swap. I understand I just can't swap the board.

greg

[inflex]

I had a hard time testing those fuses and the zero ohm resistor. Had to have my wife hold a magnifier and my probe tips are little large but here's what I got.

On the lower left fuse I got a tone and 0.00. On the middle I got nothing. No tone, just OL on the display. On the zero ohm resistor I got tone and 0.00.

greg

If you got OL on the middle one then you have a winner. That should be zero like the other. OL (in resistance mode) means over-limit / infinity as such. It would imply that it's blown open circuit.

[gibson]

Thank you! Assuming that is the problem what would the next step be?

This drive is only a month old. Would it be possible to simply buy another drive just like it and use the board as a donor, moving the ROM chip of course?

Thanks,

greg