short between 12volt and ground hard drive

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Mindfulness

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I have a client who I am doing data recovery for. This drive came from an external. I am probably going to use donordrives.com and see if I can get a replacement. Before doing so I came across a few posts on technibble about the TVS Diode going bad. I tested my drive and have a direct short between the 12 volt pins and ground. This makes sense, since the drive immediately crashes any computer I plug it into. could this be caused by the TVS diode? Any insight would be appreciated

https://dl.dropboxusercontent.com/u/66880174/2013-07-14 12.28.26.jpg
 
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It is a wd 320 or 500gb(not at the shop at the moment to give exact) . The model on the pcb
2061-701477-800 ac
 
I'm trying to wrap my head around this. Does it act like a detour for surges. If there is a surge, it creates a short to redirect the surge to the ground(path of least resistance).

Another way of putting it. You have a path from the 12v(in) that goes to power the hard drive. Between that path and the ground you have a tvs diode. If the tvs diode senses a surge on the path, it creates a short to divert the surge away from the hard drive directly to the ground.

Am I understanding this correctly?
 
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The TVS diode is probably bad and removing it will fix the short, thus letting the drive power up. The TVS diode is only rated for a certain voltage until it blows/shorts.. And once it does it is finished, like a fuse.
 
1. does the diode work as I described, is it off to the side of the circuit? I am trying to understand the concept a little better. it seems more like the opposite of a fuse, it connects when surged , not disconnects.

2. could you show me on my picture which one the 12v would be?
 
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I snipped it off with a wire cutters and started to make a clone. I have no reason to think it won't be successful!

This is the most exciting thing I have done in a long time(that even includes the bedroom)

Client is getting one heck of a great deal at $99. Currently we have flat rate of $99 for all data recovery. We are going to create 3 levels soon

I $99 all flash drives and easier logical reocvery
II $169 more advanced logical issues(have to pay for my future DDI somnehow)
III $269 if we need to do anything to the pcb or have to swap it

beyond that I will send my jobs to one of the DR companys here on the forum
 
I went to check on the clone process it was hung up at 5gb making a repetitive almost clicking sound. It said it did not have a good read for 20 seconds, the scary part was I am using the -n option of ddresue, which will skip any bad areas. I am not sure why it was hanging up. It has now been cloning without error. Keep my fingers crossed.
 
Congrats on recovering the data. I think your understanding is correct but I'm no expert on TVS diodes (or anything else). There is also a zero-ohm fusible-link resistor that comes into play, which acts like a fuse, so even after removing the TVS diode, you may not have continuity to the circuits that depend upon that 5v/12v power bus. Also, after removing the TVS diode and checking the zero-ohm fusible resistor, you should re-check for a short. The MCU, VCM and DC-DC ICs may have also be fried, so just removing the TVS isn't going to fix them. I don't think you have much to lose by just removing the shorted TVS and trying it, but the risk is yours. Make sure they don't re-used the drive unless you replace the TVS diode.
 
Larry Sabo said:
Congrats on recovering the data.
Click to expand...
Thanks, but not quite successful yet. I think the drive has other issues. I have about a 1/3 if it cloned of 500gb total. it is still making progress, about 5MB/s. The drive started making "sounds" after about 130gb from the first pass. I restarted everything, this time in reverse. The nice thing with ddrescue, it keeps track of where it left off.
 
Well, the good thing is that your client wasn't willing to spend $300 or more for a professional lab to look at it. So, let's hope you get a more complete clone before it completely crashes. If you can't, they are out their data and you are out your time and the cost of parts.
 
it is taking all my will to follow best practices and not try and get the data off the driver directly instead of just letting the clone continue. I am first cloning the part of the drive she said had all the pictures(3rd partition) using the -i option in ddrescue. Data recovery is one of the few things I am trying to keep very methodical and orderly.
 
Mindfulness said:
it is taking all my will to follow best practices and not try and get the data off the driver directly instead of just letting the clone continue. I am first cloning the part of the drive she said had all the pictures(3rd partition) using the -i option in ddrescue. Data recovery is one of the few things I am trying to keep very methodical and orderly.
Click to expand...
If it is taking this long to clone with so many issues, I'd say that you have head/media damage and options are as follows:

1. Send to data recovery pro (before you started) - > 90% chance
2. Send to data recovery pro (now) - about 75% chance
3. Keep going with the clone - < 50% chance
4. Stop the clone and try direct - < 15% chance

But, seeing that #1 path was not taken, I'm assuming that the value of the data is not worth $300 or more, therefore, #2 is out of the question too.

You could try to go direct, but if you are having this much problem getting a clone, I'd say that there is major internal damage that really requires clean room work...or at least professional data recovery equipment.
 
we ended up getting 100%
Code: 
Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued:   412755 MB,  errsize:  87352 MB,  errors:       1
Current status
rescued:   500107 MB,  errsize:       0 B,  current rate:    5259 kB/s
   ipos:   145126 MB,   errors:       0,    average rate:    5033 kB/s
   opos:   145126 MB,     time from last successful read:       0 s
Finished                 
root@linuxbox:

I was really surprised. During the first 160gb of recovery the device would stop and drop out after a few GBs. I ended up moving the drive in a different position, left a fan blowing on it and it got the data clean. the images mounted cleaning in linux, so I am sure we should have no trouble grabbing the data.

A thought just came to mind, I wonder if I have a flaky power cable, like just the 12 or 5 volt dropping out. In past experience I have had that cause a drive to make a similar sound. Moving the drive to a new position seemed to fix it. maybe that helped by putting the power cable in a better position. I will do some testing on it later.
 
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Mindfulness said:
we ended up getting 100%
Code: 
Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued:   412755 MB,  errsize:  87352 MB,  errors:       1
Current status
rescued:   500107 MB,  errsize:       0 B,  current rate:    5259 kB/s
   ipos:   145126 MB,   errors:       0,    average rate:    5033 kB/s
   opos:   145126 MB,     time from last successful read:       0 s
Finished                 
root@linuxbox:

I was really surprised. During the first 160gb of recovery the device would stop and drop out after a few GBs. I ended up moving the drive in a different position, left a fan blowing on it and it got the data clean. the images mounted cleaning in linux, so I am sure we should have no trouble grabbing the data.

A thought just came to mind, I wonder if I have a flaky power cable, like just the 12 or 5 volt dropping out. In past experience I have had that cause a drive to make a similar sound. Moving the drive to a new position seemed to fix it. maybe that helped by putting the power cable in a better position. I will do some testing on it later.
Click to expand...
That is great! See, you proved me wrong...though, I do plead my case as I was judging based on the symptoms you were describing. This is the great thing about using ddrescue with a log file. You can stop, adjust and pickup where you left off. Never reading a sector a second time.

It should be noted, DDI still requires cables and is prone to similar issues. I know that with my plugging drives in and out constantly every day, we go through a lot of cables here.

Now file system recovery will be a snap.
 
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