Seagate ST3500320AS Burns Power cable

[wakajawaka]

Hello gurus

After reading a lot of posts and learning what a TVS diode is and much other things, I think I should post my problem because I have a bunch of questions. First of all pardon my english.

I'll try to reconstruct the facts as accurately as I can.

The HDD has probably been giving problems to the PC that hanged randomly, Im not 100% sure that it was the source, but everything pointed to it and more after the issue I'm describing.

Yesterday my PC wouldnt turn on. After trying a few things, I see that it works fine when I disconnect the HDD, then I tried it (the HDD) on another computer to see what happened (bad idea, I guess). It did turn on, but there was smoke in the power connection to the HDD.

I thought (and hoped) that it could have been the cable (sata power converter), so I bought another and tried it in my PC, that is, the original one. And there was smoke again, this time the red cable (of the sata power converter) burnt faster and with much more smoke than before.

I found someone who had the same problem with exactly the same HDD in these forums, if it may be of any help.


So, I have to go shopping tomorrow to buy a screwdriver (T10, right?) to be able to see the problem in detail, but after reading the forums the TVS diode seems the most possible scenario (and hopefully no other damage!). So I want to get a new HDD to dump the data if I'm lucky and taking the diode off works.

My questions are:

1) The most obvious one, What do you guys think the problem is?

2) Maybe I fried the HDD entirely with my various tests?

3) Is my PSU probably defective? I'm far to being an expert but I get the impression that it is working fine. I would prefer to avoid buying another one but if there is risk of burning the new HDD or other components then I guess that it just has to be done.

Thanks in advance for your help. I know I should post after opening the HDD and seeing exactly the damages, but I want to know if I have to buy a PSU when I go to get the HDD and the screwdriver.

[dmarques]

Hi,

Regarding your questions:

1 - The problem is probably related with some overvoltage on the PCB, and as soon as you connect it burns something that's connected to it.

2 - That is hard to tell without making a proper diagnostic to it. But you'll get an idea after removing the TVS. If it doesn't work, the problem is bigger than just a TVS and has to be taken care by a pro.

3 - That's easy to tell, use your PSU with good known hard drive or CD-ROM and check if they work fine.

One last issue. I don't know what do you mean exactly by "opening the HDD", but you should really not open the HDD, or else you'll get it worse than it is.

[wakajawaka]

Hello. First thanks for your help.

By opening the HDD I mean exposing the logic card components as it is upside down. It has to be detached to see them. It is like this photo but with the other side of the card showing up, hope I explained myself.

[wakajawaka]

I made a post earlier and it is pending for review, but I have news. Sorry for the (kinda) double post.

So finally got the screwdriver and saw the problem. There is this top right component (black box with two connections on the sides) that is burnt. Indeed more than burnt looks "cracked" like there was a popcorn inside and just popped. There are also traces over the component that do look like burnt, two thin lines like this: -- --

I guess that it is the famous TVS, hope that the other lines are not important damage. I made pics with my shitty phone, they look ugly as hell but anyway:


http://img38.imageshack.us/img38/502/hdd1m.jpg

http://img832.imageshack.us/img832/8854/hdd2o.jpg

Thanks again.

[dmarques]

You can try to remove that one and check the results.

[wakajawaka]

I did and it worked, I were able to get my data, thank you very much dmarques.

[dmarques]

You're a lucky guy also