Hello,

I have the following hard drive: Western Digital Caviar Black WD7501AALS 750GB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5" Hard Drive -Bare Drive

Link: http://www.newegg.com/Product/Product.a ... -_-Product

About 2 days, I was trying to connect this drive as an external hard drive (like I usually used it as), and something went wrong. 1st, I plugged in the SATA power connector for about 10-20 seconds while I left the room quickly to check onto something.

2nd, when I returned something smelled weird, and I noticed that the hard drive did not spin up.

Therefore, when I tried to find the source of the smell, I noticed that it was coming from my hdd circuit board, so I quickly unplugged the drive power connector and the data cable. I did not connect the SATA to USB connector yet.

However, later on after I did some googling, I found that the 12V TVS chip might be at fault, and that if I try to snap off the broken TVS caps, I might be able to fix the problem.

So this is what I did: I carefully took off the circuit board with a hex screw driver, and tried to snap off the R4 cap on the circuit board. Then I put the circuit board back carefully with screws. Connected the SATA power connector, and no go, the drive will not spin up. And the small part of the circuit board (where the SATA power connector connects) is still heating up.

Then I disconnected the SATA power connector, and unscrewed the circuit board again. This time, I snapped the R3 cap and put the circuit board back together. This time, the small part of the circuit board does not heat up like it did before, but the drive will still not spin up. Therefore, I cannot move all my important data off to a brand new backup drive.

I heard somewhere online that "you can replace the 12V TVS diode with an SMBJ12A from Farnell, Mouser, or Digikey".

Reference: http://community.wdc.com/t5/My-Book-for ... /m-p/12526

Therefore, I have not idea which version of the "SMBJ12A" 36 caps I exactly need to replace both of these caps that I snapped off.

These are the caps that I snapped off:

LG
9BA
M

AE
02A
M


Here's a website that shows the exact picture of my hard drive's circuit board: http://www.drivestar.org/product/pcb_wd/701567.htm

Also, I was quoted $300 for the recovery (not including shipping + where they will store data).

And I cannot afford this, especially when I have to ship the hard drive, and not see the recovery in person.

And swapping the circuit board will not work for my model of the hard drive, because the main chip is the one that stores all the calibration data.

Please help me find the solution how to fix this problem with my circuit board for my hard drive, and also, if there may be any other problems with the circuit board that I will need to fix.

Any help would greatly appreciated.

Thank you very much.

Your terminology is incorrect and confusing. "Caps" are capacitors, and "TVS diodes" are diodes, not caps. The circuit reference for the 12V diode is D4, not R4. Similarly, D3, not R3, is the reference for the 5V diode. R64 and R67 (?) are the zero-ohm resistors associated with diodes D4 and D3, respectively.

The fact that the 5V diode was shorted would suggest that there was an overvoltage on this supply. Did you perhaps switch the 5V and 12V inputs? If so, then removing the protection diodes would have made your board vulnerable to further overvoltages. In fact you do not say whether you checked your power supply, or its connections, so you may now have done additional damage to your board.

I used this hard drive as an external backup drive.

I used this hard drive with the following item: USB 2.0 to IDE SATA S-ATA 2.5 3.5 HD HDD Adapter Cable.

Link: http://cgi.ebay.com/USB-2-0-IDE-SATA-S- ... 2a09a0a1f8

I have no idea why the diode fried.

Also, thank you for correcting me about the terminology. I am completely new to this, so this is why I am unfamiliar with these terms.

Therefore, I was offered to get the diode's changed for $30 from the same exact circuit board, by shipping my circuit board to China. Is it worth the price, or can I do it myself somehow? And which diodes would I need to solder to the place of the original one's that I removed?

Thank you very much.

Merely changing the diodes won't fix your problem.

I suggest you purchase a digital multimeter for US$10 and measure the resistances of the resistors, particularly R67. Do this in the absence of power.

Then, with the drive disconnected, measure the voltages at the SATA power plug at the end of your cable. Verify that they match the pinouts of the SATA power connector here:

http://pinouts.ru/Power/sata-power_pinout.shtml

Okay, I used my digital multimeter (with the diode symbol selected), and measured the resistance of the R64, and R67 capacitors.

They both show "002", then after about 1-2 seconds "001".

Also, I already broke off the original D4 and D3 capacitor, because I thought there would be a quick fix to the problem, because on some forums they said that you can just break off the capacitors and it would fix the problem, or atleast you can try.

I still have those capacitors left in a small plastic storage box.

But after I broke off the D3 capacitor, the part of the circuit board under the SATA power connector stopped dramatically heating. And since I first broke off the D4 capacitor, I guess I am out of luck on breaking the correct capacitor off and making the drive work without the over voltage protection...
____________________________________________________________________

Also, about the SATA power plug - I tried to measure the voltages, but with the ends of the digital multimeter connectors, it is almost impossible to do so, therefore, I tried connecting the SATA DVD+RW drive to see if it would work, and everything works without any problems.

However, I am never trusting my backup hard drive to a cheap $10 SATA to USB converter with power supply. Now I will purchase an external case for such uses.

____________________________________________________________________

I think what may have caused the problem in the first place is that the SATA connectors (on the circuit board - or the ATX to SATA power connector converter) may somehow got little dirty to not get exact connection with the SATA power cable, and something may have gotten fried. Because I always used the SATA to USB converter with the power supply to backup my files, and never had any problems before this happened, so I never suspected anything like this to happen.

And I tested the motor with the digital multimeter, the connections seem to be responding without any problems.

If I will ever fix this problem, I will backup all my data to 2 external 3.5" SATA hard drives with their own hard drive cases, not some cheap SATA to USB converter cable. And I will also purchase a 2.5" external backup drive, and backup all my latest updated date 2 times a week, just in-case, because my last hard drive data loss (around Jan. 2010) was complete loss, because I used an encrytion program to encrypt all files, and something went wrong. After week of trying everything - it was 100% useless and impossible to recover "anything".

Thank you very much.

How about buying the same exact model hard drive on Newegg.com, and trying to swap the circuit boards, and see if I would be able to access all my data or would the original circuit board have callibration data that would not make my original data readable without having to swap the main big chip ("the one with the big M in the pictures above").

Are there any other options, and is it somehow possible to fix my original circuit board, though I am not an electronics expect, I can probably pay somebody who knows how to correctly wire the fried components (don't know where to find someone who can move the main chip if they have to - but can try google search - if not too expensive).

Thank you very much.

Could have been a total recovery, instead. But not at end-user level, especially if the encryption key is not known anymore (what was used for encryption ?).

Swapping PCBs won't work...

You need to know if the preamp inside the HDA is OK otherwise it can fry the new PCB...

Finally : if the MCU in your original pcb is fried too, it's definitely game over for you but can be solved with professional equipment and know how.

Can you post here where this "good advice" about removing / cracking components was found ?

About the other hard drive (Jan. 2010), I had the original encryption key, and encryption file, but since I was re-installing windows 7 and forgot to unplug the USB to SATA connector, I guess it over wrote the boot sector of the encrypted drive, and I did not create any recovery boot disks, so I guess that was over for that drive.

About the MCU chip, I never said it was fried, I was just asking if moving the original MCU chip to the replacement board is the only other option.

Also, how do I find the preamp inside the HDA?

And finally, I found some very useful info at the following link, which provided me with the correct capacitor names that I need for the repacement to be done:

http://community.wdc.com/t5/My-Book-for ... 6292#M1619

Thank you very much.

About the hint; here's the link to the post where I read about snapping the TVS chip off:

http://community.wdc.com/t5/My-Book-for ... /m-p/12670

User: fzabkar
Time of post: 02-26-2010 02:35 PM

Thank you very much.

D3 and D4 are diodes, not capacitors. If your resistors are reading 001 or 002 on the 200 ohms range, then they are OK.

The fact that your USB-SATA adapter works with your optical drive would suggest that the +12V and +5V supplies are correctly wired. However, it may be that the 5V rail is a little on the high side. You should be able to sneak your multimeter probes into the Molex plugs. Yellow is +12V, red is +5V, black is ground.

BTW, whenever I suggest removing a shorted diode, I always warn people that the affected supply rail will no longer have any overvoltage protection. This means that you must ensure that your power supply is good.

Need to know if preamp is still ok, then if mcu is ok otherwise it's total loss of time. 'moving the mcu' require special equipment too to make it safely. The rest is TOTAL BULLSHIT. In any case even if everything is fubar, but the fw on the disk is in decent conditions, it is still possible to rebuild a working pcb. Not at end user level with a multimeter, anyway.

I already purchased the replacement diodes, under the following part #'s: SMBJ13A, SMBJ12A, SMAJ5.0A

(Note: one of the part #'s is the replacement diode's for my laptop hard drive - either the 13A or 12A part #).

And once I will replace the D3 and D4 diodes, which were probably burned, then I will carefully solder the replacements, and try to use the hard drive in a 3.5" hard drive case (not SATA to USB converter), just to make sure no further damage will be done.

So far, all the items that I have purchased total about $80 - $90, and once I will buy the correct soldering iron (battery powered, or butane), around $20 or so, the total cost will be over $100. Atleast I will not have to pay $300 - over $1,000 for such data recovery. Just have to wait for all the ordered items to arrive now.

Thank you very much.

Must be an epidemy : it was you with a fried fujitsu too?

Yes, I was originally using my laptop hard drive with the 160gb Fujitsu hard drive, but for some unknown reason, I failed to think straight and decided to connect the SATA power connector to the drive (thought it could not happen), even though the SATA to USB converter adapter cable was intended only for the 3.5" SATA drives, and for 2.5" IDE laptop drive (no power connector use).

Therefore, I will never trust the SATA to USB converter cable again.

Now I will also get brand new, 1x 3.5" SATA backup drive (with proper external case), 1x 2.5" USB backup drive (with proper case), backup all the data once a month - and backup 2x a week all the updated data (such as documents, music, etc.). - Just in-case, because the first time when I lost all my original data due to encryption problem, I spent about 1 month trying everything, then eventually I gave up - it made me so mad. And I do not want anything like this to happen again.

And the laptop hard drive had all the most important and updated documents (login information - accounts, etc.), e-mail, music, college documents, etc.. - about 20-30gb of extremely important data (without that data - my online world is lost..).

I hope I will get them both fixed - I will have to purchase a butane soldering iron, and use that for soldering the replacement diode's, since it is precise, and the soldering iron tips included with the butane soldering iron kit are very small, and precise, and there are also some others, just in-case I will need them (about $20 in The Home Depot + around $5 for butane refill). Already purchased the correct pliers too (just in-case - because the components should be very hot), now I just need the eye safety googles.

Tried to use an electric soldering iron - the worst experience ever - nothing could be done - never really did get the capacitors replaced on the older lcd monitor to fix the screen problem - so I just threw it away.

Thank you very much.

Instead of doing all these Wile E. Coyote-ish attempts (that can potentially end in a disaster) there are a lot of pros in your area from this forum who can handle your case professionally and safely.

If you were here it would have been diagnosed first and even if the problem goes beyond PCB or PCB completely gone it could have been solved in less time than you think (NO you could not stay in the lab , we both have privacy concerns and trade secrets - before you say something - jokes apart, a professional is called so because he is trustable and has 1st in mind your data privacy) using the right equipment and know how , not bullshit.

What else to say ? Good luck as you really need it. And don't open the drive.

P.S. your drive would work (without the mild protection they give) without the removed TVS , if I recall everything correct. If doesn't work without, the PCB has other BIGGER problems and don't expect to make it work again putting back TVS/s.
Hope the problem is just on the protection. If not, be prepared either to live without your data or get professional help as there would be no other option.

I tried to put the circuit board back, and tried to connect the drive (last week - although I forgot the SATA converter adapter might be the problem), without the 2 TVS diode's (the 2 big one's on the inner side, below the SATA power connector), and no go, the drive will not spin.

Therefore, once the correct replacement TVS diode's come, I will use butane soldering iron, and solder in those replacement diode's. Then I will ask my brother to connect the drive to his desktop computer, and see if it would work or not.

If it would not work, or spin up, then within 30 days when I will get enough money, I will go to Fry's Electronics, and pay then $150 to try to do data recovery. Hopefully, they would be able to do that.

Thank you very much.

The new TVS diodes won't save you now. The damage was already done, either in the first instance, or later when you exposed your unprotected drive to the same overvoltage that killed your 5V diode.

First advice : (copied from the thread outside the forum but referenced in the original post)

"However, PCB replacement should be your last option. The fix may be as simple as removing a shorted 12V TVS diode by snipping it out with side cutters. The Seagate discussion that I referenced shows just how easy the solution can be. Two people with no prior knowledge of electronics or multimeters were able to resurrect their broken drives."

Later : (quote)

The new TVS diodes won't save you now. The damage was already done, either in the first instance, or later when you exposed your unprotected drive to the same overvoltage that killed your 5V diode.

Bingo.

A simple cold became a bad pneumonia

_________________
Murphy was an optimist

Datarecovery in Belgium, Holland, France and Germany
Datarecoverytools http://www.drtools.eu

I would not be so sure about that. The Western Digital Caviar Black hard drives are pretty good, so I am not willing to give up now.

Because today, I was able to repair my other laptop hard drive, after I tried to do a circuit board swap with the same model of the circuit board as my original laptop hard drive circuit board.

Once the replacement diode's will come by mail, then I will replace the original diode's with butane soldering iron, then purchase the 3.5" external hard drive case (not a cheap $10 USB to SATA converter adapter cable), and see if the drive will work.

If it will work, then I will backup all my data off that hard drive, and then after I will purchase the new 3.5" hard drive, I will move all my files there.

Then I will just sell this hard drive on eBay, because after such a problem, I do not think I want to trust this exact model of the hard drive anymore. I was originally off much better with the Western Digital Caviar Green 500GB SATA hard drive, which I never before had any single problems all all, then after about 10 months, I decided to upgrade to a larger drive, because it was on sale for $20 less than original price on Newegg.com, but now I think I rather stick with the 500GB hard drive model than this one, even though this hard drive includes a 5 year limited warranty on parts and labor. And if I will be able to get replacement screws, then after formatting, I might be able to send the original one back to Western Digital, and get a replacement, just in-case.

Thank you very much.