Hitachi Deskstar blown D2 diode

[nine3o]

Hi all,

I have a deskstar model HDP725050GLA360 with a blown D2 diode and a shorted D3. Using these forums (thanks to all who post in here) I have figured out what D3 diode does.

I have removed D3 diode since it reads 0 ohms in either direction.

Can any one tell me what D2 does? I just want to recover data and pitch the drive once done.

See image for details (borrowed the picture from another thread)

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[Cleanroom]

pop them both off and the drive "should " spin up and read. Get your data off then chuck it

good luck

[Nick_CT]

I have removed D3 diode since it reads 0 ohms in either direction.

Can any one tell me what D2 does? I just want to recover data and pitch the drive once done.

See image for details (borrowed the picture from another thread)

One is for the 12v rail, the other is for the 5v rail.

[fzabkar]

The diode marked "14" (D3) appears to be a 12V TVS diode. It is probably rated for 12V working voltage and 14V breakdown voltage.

The part marked "Z2" (D4) is the 5V protection diode. I'm not sure whether it is in fact a TVS diode -- the marking is more like that of a 5.1V zener diode.

The diode marked "S3" (D2) is in parallel with the 12V TVS diode. It could be a SD101CWS Schottky diode:
http://www.diodes.com/datasheets/ds30078.pdf

It would have a lower forward voltage drop than a TVS diode, so I expect that its function is to provide protection from reverse polarity. Its reverse voltage rating is 28V, so it should survive typical overvoltages, such as those from a 19V laptop supply.

[nine3o]

Thanks all for the info, I removed both diodes and drive powered up, recovered all my data and pitched the drive.

Much appreciate the help and the info on this forum.

[jurisk]

Thanks all for the info, I removed both diodes and drive powered up, recovered all my data and pitched the drive.

Much appreciate the help and the info on this forum.

Hi nine3o,

Could you please briefly explain how to remove these diodes?

I have a similar problem, thank you for any advice!

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[Cleanroom]

use a soldering iron, heat gun, or you can use clips to clip them off.

All of these option you need to be careful with.

I would see if you have any friends, or a local electronics shop that can remove them for you if you are not comfortable doing it.

[fzabkar]

Could you please briefly explain how to remove these diodes?

I recommend flush cutters:
https://dlnmh9ip6v2uc.cloudfront.net/im ... 029-01.jpg

[jurisk]

use a soldering iron, heat gun, or you can use clips to clip them off.

All of these option you need to be careful with.

I would see if you have any friends, or a local electronics shop that can remove them for you if you are not comfortable doing it.

Could you please briefly explain how to remove these diodes?

I recommend flush cutters:
https://dlnmh9ip6v2uc.cloudfront.net/im ... 029-01.jpg

OK, I will try.
Thank you very much for your replies!

[jurisk]

Seems I still need some help:

I replaced the diodes (please see the picture 1).

Should I try to put a tiny layer of allow to make a connection where the diodes are missing? Is it too risky for the drive? OR shall I find and buy new diodes for the replacement?

Sorry if I am asking the questions which have already been covered before in this forum.

P.S. I also bought almost identical HDD with the similar PCB, in case if the only solution is to swipe PCBs. In this case, shall I swipe the ROM chip from the burned PCB to the donor PCB before I try to read the data drive?

(please see the picture 2 - I hope I identified the ROM modules correctly)

Thank you for your advices!

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[sathyan]

you don't need to replace the diodes.Remove it and power on the drive.
These are for protection and the drive will work without them.
But you have to use a good power supply(SMPS).

Can't properly see what the Chip number is in your picture to identify the rom.(post the writings on the IC to identify)
You can try to connect the drive without the diodes and check if the drive powers on.
Mostly the drive Should work and you can get to your data.
Else , identify the rom chip ,and swap it