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Electronics => Repair => Topic started by: UberStrike88 on December 24, 2016, 12:17:57 pm

Title: Hard drive with a broken diode?
Post by: UberStrike88 on December 24, 2016, 12:17:57 pm
Hello nice people :),

I have an old hard drive that stopped working and when I took it out of the mashine it had a boldge on a diode, The 2 diodes next to each other have the same part no. But I can't find anything about them on the internet. I know they are from on semiconducters but that's it. Here are the 2 picures and the whole board. The one with the LG. on it has that blodge on it. Anyone has an idea?
THe one with LG: http://i.imgur.com/moSYkqm.png (http://i.imgur.com/moSYkqm.png)
The one next to it: http://i.imgur.com/H8YehV9.png (http://i.imgur.com/H8YehV9.png)
And the whole board: http://i.imgur.com/m1GQ6cJ.jpg (http://i.imgur.com/m1GQ6cJ.jpg)
Does anyone have an idea with what I can replace the diode?
Title: Re: Hard drive with a broken diode?
Post by: KhronX on December 24, 2016, 12:35:22 pm
Seeing as those are on the 12v and 5v supply lines, you can bet your booty those are a pair of TVS (transient voltage suppressor) diode.

https://en.wikipedia.org/wiki/Transient-voltage-suppression_diode

Technically, the hard-drive should work fine with those removed, but will be left somewhat unprotected in case of any surges on the supplies.
Title: Re: Hard drive with a broken diode?
Post by: UberStrike88 on December 24, 2016, 01:13:36 pm
Seeing as those are on the 12v and 5v supply lines, you can bet your booty those are a pair of TVS (transient voltage suppressor) diode.

https://en.wikipedia.org/wiki/Transient-voltage-suppression_diode

Technically, the hard-drive should work fine with those removed, but will be left somewhat unprotected in case of any surges on the supplies.

Alright thank you mate I will remove them and see if that was my issue or if my psu destroyed something past the diodes.
Title: Re: Hard drive with a broken diode?
Post by: wraper on December 24, 2016, 01:19:49 pm
I would advise immediately stop using PSU which was powering this HDD, and as minimum check if electrolytic capacitors inside it are not bulged. Otherwise more damage may follow.
Title: Re: Hard drive with a broken diode?
Post by: KhronX on December 24, 2016, 01:25:54 pm
That's a good point, actually  :-+

I would advise immediately stop using PSU which was powering this HDD, and as minimum check if electrolytic capacitors inside it are not bulged. Otherwise more damage may follow.
Title: Re: Hard drive with a broken diode?
Post by: Inflex on December 31, 2016, 04:57:30 am
Was this from an external drive at all (3.5" I'm presuming?).

I get a few drives in each year with blown (shorted rather) TVS diodes and they're always from external enclosures.

Good advice from Wraper, especially if you do remove the TVS's and it comes good again, last thing you want to do is blow the board with a glitch. 

Usually I always just clone the data/drive with ddrescue straight to an image and write off the old drive as an overly paranoid precaution :)