The internet has many examples where freezing a hard drive has helped gain access to data following a failure. While this may work in a small number of cases, it could cause irreparable damage, leading to a situation where data recovery is extremely complex or even not possible.
It is part of human nature to look for cheap and simple solutions which could save time and money. It is important though to understand the consequences of trying this approach, and why it may complicate the data recovery process, or even make it impossible to recover data at all. If your data is critical to you or your business, it is of the utmost importance that you do not take unnecessary chances.
Heat is generally a bad thing for hard drives, and the theory is that by freezing it, you cool the components to a temperature at which they will successfully work. There is plenty of anecdotal evidence that this can succeed, but there are side-effects.
Success is Limited
Even if you are successful in reviving a failed hard drive, it is unlikely to keep working for long enough to recover any significant amount of data. Once powered up, a drive will begin to rise in temperature rapidly, giving little time in which to attempt copying data from it. That is if it stays running for long enough to see the data volume mounted by the operating system.
The tolerances inside the hard drive are to a high precision, and the act of freezing the components could see this upset by even the smallest difference in contraction rates of the various materials used in the manufacturing process. This could lead to an unwanted resonance, setting up vibrations which could cause the read/write heads to impact with the surface of the platters, destroying data as they scrape across the disk.
Data Recovery Could Become Impossible
Another possible side-effect which needs to be considered is what happens when cold materials are in contact with the atmosphere which is considerably warmer. The water vapour present in the air will condense onto cold surfaces, leading to a rapid build-up of moisture. This moisture will reach a point where it becomes water droplets, which can lead to many problems, both internally and externally.
Water is a conductor, which could lead to a malfunction of the electronic components through a short circuit. Inside the hard drive, if any water condenses on the surface of the platters, it could come into contact with the read/write heads. This may either damage the heads on contact, or cause them to bounce which will result in the heads impacting with the disk surface.
Even if the drive survives and works for a short period of time, any further attempts at freezing will be sure to result in failure. Any moisture or water droplets which formed during the first attempt will freeze. If these are internal to the drive, it will cause untold damage once the drive is powered up again, either through component seizure or frozen water destroying the read/write heads and in turn the surfaces of the platters.