30/6/2017 – ST4000DM000 – Contamination inside the disk
A Seagate ST4000DM000 hard disk drive was received from a Manchester-based media company. The HDD was from an external “Backup Plus Hub” USB3 caddy, and had been knocked off a desk by one of the employees whilst he was working on a project. The drive contains many gigabytes of video footage and the associated Adobe Premier editing project files.
On arrival, the HDD was making a buzzing sound. The platters would not spin up. Initial diagnostics suggested that spindle motor was seized as a result of bearing failure, or the head assembly being parked on the platter surface. This is a mechanical failure.
This model of Seagate HDD has a locked diagnostic port, with an encrypted service area. Consequently, certain alterations to the firmware are either very difficult or impossible to achieve at the time of writing.
Above, opened ST4000DM000. Heads are parked on the platter surface. There are silver coloured fragments located in the drive (circled in white). These are likely to be parts of the damaged platter surface. Recovery was possible.
Hard disk drive details:
Manufacturer: Seagate
Model: ST4000DM000
Part Number:
Printed Circuit Board:
Recovery result:
The hard disk assembly was cleaned of contamination. The heads were removed from the platter surface and inspected under magnification. Head #3 showed signs of some physical damage. The head assembly was replaced with that of a good matching disk. The repair of mechanical components was successful and it was possible to initialise the HDD to a reading state. Selective head imaging was completed to read from heads 0, 1, 2, 4 and 5 before read attempts on head 3 took place. This was to minimise the risk that the donor parts would fail to avoid reading the platter which was most likely to be damaged.
This work has taken place today, and the HDD is now cloning with a small number of read-errors. We expect to recover 99.9% of the data OK.