Barracuda XT, Barracuda, Barracuda Green, DiamondMax and other desktop SATA and IDE drives

[B1r0]

Hello,

I inverted the 5v and 12v power lines on a sata power connectors and burnt 4 hard drives.

They may be recoverable but I need to identify the components to replace them.

These are 2 SMD that looks like resistors(maybe 0ohm?) and a TVS Diode.

I'll be very grateful to whom might help me in this.

Please, have a look at these pictures to see the components.

http://imageshack.us/photo/my-images/17/imag0062tc.jpg/
http://imageshack.us/photo/my-images/10/imag0053xj.jpg/

Thank you,

Biro

[fzabkar]

I believe the burnt components may be inductors rather than resistors, but the solution is the same in either case, and that is to replace them with wire links.

The two semiconductors are 5V TVS diodes. They can both be substituted with an SMAJ5.0A. That said, the drive will run without the diodes, but you will be without overvoltage protection until you replace them.

See http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

If the diodes have not been able to contain the damage, then you will need to transfer the 8-pin serial flash memory IC (Winbond 25X408LS) to your replacement board. This IC stores unique, drive specific information.

The following PCB suppliers offer a firmware transfer service, either for free, or for US$10:

http://www.donordrives.com
http://www.onepcbsolution.com
http://www.hdd-parts.com

I would advise that you avoid those suppliers who don't tell you that a board won't work without modification. Often they will attempt to obscure the requirement for a firmware transfer by deceptively describing their products as being "for data recovery only".

[B1r0]

fzabkar,

Thank you very much, I've read your TVS diode FAQ and I must give you kudos on how well is written.

I have many broken harddrive and I will try to fix the drive with a TVS from one of them.

I'm now concerned about what you say are inductors.

I'm good with the rework station but my electronic knowledge is very basic.

What is its purpose where it is located?

I assume as additional protection.

I'd like to replace them rather that wire link their place.

I have a L/C multimeter, how you would use it to measure the induction of the component.

I guess as a capacitor it cannot be measured on the PCB.

I want to save the drives, but I don't mind about their content because I've a backup and I don't want to spend money to buy new PCBs.

Again, thank you!

Your help has been very much appreciated.

[fzabkar · Accepted solution]

Most Seagate PCBs connect the TVS diodes directly between supply and ground. Yours is one of the few that include a series connected component, either in the supply, or in the ground return. Other manufacturers (eg WD and Samsung) use zero-ohm resistors in these locations. These components fail gracefully, without fireworks. Therefore I suspect that they are fusible resistors.

In your case, however, since the components are not fusible, I believe that they must be inductors. Furthermore, I believe that the inductor and capacitor constitute a low pass LC filter that removes high frequency noise from the supply.

I expect that the circuit would look something like this:
http://upload.wikimedia.org/wikipedia/commons/e/eb/Lowpass_Filter_LC.svg

The inductor (L) could be at the positive end (as shown), or in the ground return, or both.

There would be similar inductors in the +12V supply, so you might like to measure those for comparison purposes. If you really want to replace them, then I would pay attention to their current rating. They would need to be able to carry the full spin-up current, although this would affect the +12V supply rather than the +5V.

[B1r0]

The drives are working again!
One of them had the copper rails between inductors and in-power completely gone fused.
I had to use very thin copper wire to rebuild, a bit messy, but it works.


Thanks fzabkar, I couldn't have succeded without your help.
Biro