When there is a hard disk with one damaged platter or head, can one platter be removed and the disk made workable again with reduced capacity?

The firmware might autodetect the number of available platters during power up. Maybe the same firmware is used across a HDD range and so supports drives with different numbers of platters.

Note: I am not asking about interchanging platters, but about reducing the number of platters.

Assume that the damaged platter or head can be removed in clean room conditions.

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    Hard drives have tolerances measured in microns not yards. If you opened it, it's dead. Forget it. Throw it away. You broke it irreparably when you opened it.
    – Tetsujin
    Apr 1, 2018 at 16:13
  • Repairing a hard disk? Not possible without intimate knowledge of the product internals, ... and it probably requires tools to (physically) calibrate it.
    – Hannu
    Apr 1, 2018 at 16:29
  • @Tetsujin: I know. There are possibilities and guides on the internet on even how to swap platters between identical drives, provided careful working in a clean environment. So, that should not be the prinicipal problem. Apr 1, 2018 at 16:32
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    If you're comparing the cost of discarding a dead HD against the cost of clean facilities for multiple repeat operations over several years, then your point may be valid.
    – Tetsujin
    Apr 1, 2018 at 16:37
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    @JakeGould: Yes, you got me. In fact, after opening the drive the academic question if it would have been possible to use it with a removed platter if I had been opening it under clean room conditions came up. And I mixed up and simplified things here, which lead to "digging my own hole". Apr 5, 2018 at 8:53

1 Answer 1


There is NO way to know what the firmware is really doing without reverse engineering it.

There is NOT a standard firmware or hardware platform for hard drives, only a standard host interface.

For a long time hard drives have supported "sector sparing", and will report when this occurs via SMART, but no information is provided on where the spare sectors are, etc. Given this it's likely that the firmware would try to address defects on a sector level and not a platter level.

As @Tetsujin says, if you opened it, it's very very likely completely dead now. Hard drive heads float microns above the drive surface, meaning normal particles in air will cause the head to crash. Data recovery companies open hard drive platters in clean room conditions where there is no dust.

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