Freeze It Heat It Hard Disk Recovery Myths


In old days, before IDE, the older drives from the mid-80s that used stepper motors, functioning of hard disks were sensitive to heat and cold. But over the period, hard disk manufactures developed materials that are less or marginally affected by heat and cold. Remember the Monday morning blues error that resulted bad sectors showing up on hard disks. This happened in cold weathers, especially after the computer being off overnight or over the weekend (thus the name). These stepper motor hard disks could not compensate for thermal expansion of the disk platters and might not be able to read the tracks on the drive until the disk has warmed up. Waiting a half-hour might see the problem go away, but in the long run the disk will need to be low-level formatted again. None of this applies to modern IDE or SCSI hard disks.

In view of the above, the freeze-it myth is exciting and makes some sense, but the consequences might be a disaster. The modern hard disks have read/write calibration mechanism so that the heads are properly positioned over the disk surface at a determined heat or cold tolerance. This enables the heads to read and write the correct tracks without any kind of error.

These parameters are recorded in ROM memory located on the logic board in some models and series AND/OR one part in ROM and the other in EPROM. In some models, the parameters are recorded in some types of flash memory located inside the drive. This is the reason why sometimes the replacement of a burned logic board does not recover hard drive even both drives are identical using same firmware version. This indicates that something is wrong on the inside.

In addition, there's also a type of surface recording called "servo", installed during the manufacturing process of the hard drive. The "servo" helps the heads to correctly positioned while running.

This resulted someone to put a hard drive in freezer and connect back it to PC. The system recognized the drive and worked again for several minutes. Then again freeze the hard drive it worked for a few minutes more, providing some more minutes to save some information from the hard disk.