Harddisk Demagnetization

Can the harddisk be reused after demagnetized?

The harddisk was working very well before demagnetization. After erased all data on the harddisk, the harddisk cannot detect by computer. I would like to consult is there any expert give me an advise that can re-use the harddisk. Otherwise, it because rubbish.


If you really mean “demagnetized” (using a tape/harddrive demagnetizer), then all magnetic information is gone from the harddrive including low-level formatting.

I don’t think it’s possible to reuse the harddrive after that, since I don’t think there’s any user operable tool available to do actual low-level formatting on modern harddrives.

(Tools you can find by googling that claim to perform Low-Level Formatting on harddisks, can perform operations such as zeroing and partitioning, but they don’t perform Low-Level Formatting in the original sense of the term, which is necessary for the drive to locate tracks and sectors)

Welcome to the MyCE forums.

Can you really de-magnetize a newer HD with anything available to the public? I took a 2 TB HD apart and it had the strongest magnets that I have ever seen. I’ll bet you could tow a car (If you could find any metal to attach it to) with these magnets.

from what i remember theres some data on the reserved part of the hard drive that the drive needs to function and if thats gone its dead afaik.

[QUOTE=G_Ivan Awfulitch;2667186]Can you really de-magnetize a newer HD with anything available to the public?[/QUOTE] If you by “public” mean a company that can afford to use 5-10.000 dollars on something like e.g. this, then yes.

Once a hard disk is demagnetised (degaussed as it’s mainly referred to), all the calibrated reference points on the hard disk are also erased. This means that once the hard disk is powered up, the heads cannot tell one location from another, much like as if the platters were removed.

As far as I’m aware of, only the hard disk manufacturers have the ability to create the reference points on the platters and I’m fairly sure this is done by specialist equipment and cannot be done by the hard disk itself. So this basically means that once a hard disk is degaussed, it is junk.

So, what’s the chance of a magnet with enough power to degauss layers of disks leaving all those cute li’l ROM chips unaffected?

[QUOTE=ChristineBCW;2667337]So, what’s the chance of a magnet with enough power to degauss layers of disks leaving all those cute li’l ROM chips unaffected?[/QUOTE]

I was thinking the same and if the degaussing is strong enough what about the head and platter motors?

I was thinking the harddisk could be reconstruction by Low-Level formating. However, the harddisk after demagnetized, no computer can detect the devices.

The demagnetization should be targeted on the harddisk platter but not the electronics circuit. Am I corrected ? Does anyone know why ?

By the way, I was also thinking about the degaussing may affect the motor which inside the harddisk (becasue the magnet inside the motor). But I can tell that, once the power is connected the motor is still rotating. Not sure it is functioning or not.

well the reserved part of the drive (some section on one of the platters) contains the claibration data and on some hard drives some or all of the firmware.

I have a feeling the ROM chips - which pass out all the instructions to the motors and everything else - operate with a degree of magnetized particles. Degaussing those probably wouldn’t take a lot, either. “This only affects the Zeros, though - it will leave the 1’s. That should be fine, right?”

Of course, the silicon itself may be unaffected but all those teeny little transit paths (“traces”)… those aren’t exactly biomatter.