Data Recovery Myths - Part I

The “Freeze It’ Myth, The “Heat It” Myth, And The “Firmware” Myth


The freeze it myth is interesting and makes some sense, but the consequences are a disaster!

During the manufacture of a hard disk drive it’s necessary to calibrate the read/write mechanisms so that the heads get correctly positioned over the disk surface at a determined tolerance, in order to allow the heads read and write on the correct tracks without any kind of error.

Some manufactures, in some models and series, record all those parameters in a ROM memory located in the logic board, or a part is recorded in that ROM and another part in an EPROM or some kind of flash memory that’s inside the drive. This explains why many times the simple replacement of a burned logic board for an identical one using the same firmware version doesn’t make the hard drive come back to life: something is wrong on the inside.

There’s also a kind of surface recording that’s made during the manufacturing process, which is called “servo”, that helps the heads to position correctly. Many times that factory magnetic recording is altered by some reason related to the surface material, and the head starts moving back and forth.

Someone suspected it had some relation with temperature effects and decided to freeze the hard drive in the freezer and then run to connect it back to the PC, and bingo! The drive was recognized and worked again... for some minutes. New freezing session and the drive worked for some more minutes, enough to save some megabytes of information. Then the disk stops working for good.

We’ve read in a forum that when we freeze the hard drive, its interior gets “rearranged” and everything goes back where they belong. This information makes some sense, since the retraction of the material due to the low temperature could have helped the read heads find the tracks again, in some cases. But why the drive stops forever?

Because the disk’s magnetic surface was highly degraded and there comes a time when the “freeze/heat” doesn’t work anymore. The result: the few chances of recovering a good part of data have maybe gone to space. Not to talk about the condensation of the air inside the hard disk (yes, the HD has clean air inside it, a filter to prevent impurities, and a dehumidifier sachet). Read our tutorial Anatomy of a Hard Disk Drive to see this.

One more myth “busted”. Regarding the heat it myth, well... I think there’s no need to comment on this, but there are people who commit and support this crime!