We recently received these four drives for data recovery. Now, hard drives can indeed handle some heat, and we have successfully recovered some drives whose exteriors were completely charred to black; but this particular job is among the worst fire damage we’ve ever seen.
Before opening the drive, we notice the black plastic surrounding the SATA ports were a bit distorted. No big deal, plastic starts to melt around 200 F, and high rpm SAS drives sometimes run themselves up to 150 F.
Next we removed the board, and we noticed some loose components including the relatively large controller and ROM chips. This is concerning because solder doesn’t melt until around 400 F. At this point we remained hopeful, however, because we have the expertise to repair and/or replace boards with great success.
Finally we removed the lid (which has been rubber-cemented to the body by the melted silicon seal), to reveal a scene which might be claimed by a postmodern sculptor. The video above paints the whole picture, but the two most significant features include the rainbow-patterned platters and demagnetized head magnets. Hard drive platters are glass or metal discs, which withstood the heat as expected, however these discs are coated with a magnetic layer upon which the heads may read and write data by flipping magnetic bits. Under the intense heat, this magnet layer crinkled up like wrinkle-paint on your automobile, marked also by the same rainbow sheen found on case-hardened metal. The slightest blemish on a platter surface is most often a death sentence in terms of data recovery, so our prognosis was complete here. What was most interesting, though, was the head magnets. The heads are controlled by electricity via a pair of rather powerful neodymium magnets. When we tugged on the top magnet, it came up effortlessly, completely demagnetized. For perspective, the Curie temperature (at which demagnetization occurs) for this magnet is about 600 F.
Unfortunately, this data is toast, but it’s quite an interesting reminder to not only back up your data, but back it up off site! (or in a fireproof safe)
Thanks for reading