Sunday, January 13, 2008

Hard drive failure

This summer, when we went to my father and mother in law, I decided to format my HD, reinstall everything and make an image of the freshly installed and tweaked system. On my late Toshiba Satellite M35x, this took about five hours. With the amount of experiments I do, it is not logical to waste so much time every time I mess up beyond repair, so I decided to immediately put the image of the HD on a DVD. So, I took out the 9 months old Samsung 80GB, 5400rpm HD on my wife's desktop and finish the work. I set it up, started Norton Ghost and in less than half an hour, the image was on my wife's computer. Then I went crazy. I decided to take an old Toshiba HD that a professor of mine gave it to me as a "payment" for an operation I performed on his Dell laptop, and see how it would perform. Now this HD was in a poor shape. Due to the Dell's clogged cooling system it got cooked in only a few months and developed a ton of bad sectors. So, I used WD Diagnostics, a free but very efficient tool to mark out the bad sectors, and then the Toshiba HD did work fine. I placed the image installation onto the Toshiba HD, mounted it in my laptop and booted up. Everything worked fine. Then I decided to play around with the disks. I put the Samsung in a 2.5' USB tray and plugged it in my wife's computer, and noticed a small spark when I touched the USB cable to the HDD. Then when I tried to plug it on my laptop, all I heard was NOTHING. So, I pluged it back on my wife's comp. without any sucess. I could not believe that I just destroyed my hard drive and all the papers with it. So, I figured, I have the warranty, I can take it to the store and get a new one, but that would mean that I will never see my documents again. I also thought that I am not ready to pay ridiculous amounts of money so that a guy just like me would retrieve the data in the same way I would. So, I decided to forget about the warranty and go ahead and play with the drive. I figured, the only thing I would lose in a worst case scenario is the $120 I paid for the drive. Paying for data retrieval was out of the question. So, I opened the dead HD with the intention of moving the plates to another HD who had good mechanics. I know that this has practically no chance of working... but hey, I had nothing to lose (not any more), and I was dead board without an internet connection.
Now, knowing that the read/write heads are not supposed to touch the plates, and the only thing that keeps them floating is the air flow created by the rotation of the plates (just like airplanes fly), I was surprised and relieved to see this situation, presented on the photo:

As you can see, the r/w heads are not where they are supposed to be. The very fact that the plates are not spinning and the heads have landed on the plates is a clear sign that this HD will definitely die very soon. As I read online, the sensitivity of the heads and plates, a potential physical contact on a microstructural level would do damage that is equivalent if you take a 12 story building and drag it along an asphalt road. It will destroy both the road and the building. So, that meant that I have a somewhat destroyed r/w heads, micro chips that have teared off the heads and plates... and the worst of enemies - dust particles. My bedroom is no "clean room" so there is definitely more than 100 dust particles on a cubic meter. There are millions, and not so small particles either. Anyways, as things are, the disk is ready for burial. So another scratch or two wont do any crutial difference. So, I slided the heads off the plates onto their resting place. The next photo is to illustrate where the heads should be (this is actually a different HD, but you get the idea of where the heads should be positioned when the HD is turned off):

After sliding the heads off the plates, I closed up the HD, plugged it back on the USB tray, the computer recognized it fine, and I started copying the data. The copying lasted for about 10 minutes and then errors started appearing. They got so bad that a normal copying did not do the job any more. So I used WinHex to copy the last few documents. They were a bit damaged, but WinHex helped in editing them so the entire process finished with 100% successful retrieval of all my data. The only loss was the actual hard drive... which in the long run did not mean so much because I had the old Toshiba HD that worked... and a couple of months after this event the laptop itself died. But that is another story.
What we all should learn is that USB hard drives are very much different from memory sticks. The disks have moving parts and they have to go through a procedure for removal, so always do the "Safely remove hardware" in order that the HD may safely shut down. Next, have a good grounding of the desktop, because you may end up with a fried component because of the poor grounding. The third and most important lesson is that you must always, always, under any circumstance, have a second computer, 2.5-3.5' adapter, torx screwdrivers, good forensics software and crazy enough mind to open the HD when it refuses obedience.

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