Can HDD head be replaced?

When a hard disk drive (HDD) starts malfunctioning, the issue is often traced back to a faulty read/write head. Naturally, one of the first questions asked is whether the head can be replaced to restore the HDD to working order. The quick answer is yes, HDD heads can be replaced, but it’s a delicate process that requires special tools and expertise.

Table of Contents

What is a HDD head?

A hard disk drive stores data on quickly rotating platters inside the drive enclosure. The read/write heads are what record data onto these platters and read that data when requested by the computer. There is usually one head for each platter surface (top and bottom).

The heads float just above the platters on a thin cushion of air as they move back and forth across the platters to access data. They are affixed to an actuator arm mechanism that has nanometer precision control to position the head over the exact location of data requested. When in operation, the heads never come into contact with the platter surface.

HDD heads are incredibly tiny and fragile. The slider containing the read/write element is often smaller than a grain of sand. Any dust or damage can prevent the head from floating at the correct height or position properly over data tracks. That’s why HDDs must be assembled in dust-free cleanrooms.

Why do HDD heads fail?

There are several reasons an HDD head may fail, including:

Mechanical failure – The actuator arm mechanism is a mechanical device that can wear out or break over time.

Contamination – Dust buildup on the heads or platters can cause the heads to stick.
Scratches – Any scratches or bumps to the platter surface can cause issues for the heads.
ESD damage – Static electricity discharge can fry the tiny electronics in the heads.

Debris damage – Loose particles inside the drive can strike the heads at high speed.
Drive failure – Issues with the motor or bearings can cause platter wobble that damages heads.
Overheating – Excessive heat beyond specifications can deform the head slider and components.

The result of any of these failure mechanisms is often the inability to read or write data reliably. The heads are just too damaged or misaligned to maintain the nanometer accuracy required. While modern HDDs have some spare sectors to remap bad sectors transparently, once head damage progresses beyond a certain point the drive will become unusable.

Can HDD heads be replaced?

Yes, it is possible to replace the read/write head assembly inside a hard drive. However, head replacement is a very delicate process reserved for professional data recovery experts. Special equipment called a cleanroom is used to safely open the drive and replace the heads. Amateur attempts usually result in a destroyed drive.

The basic process involves:

Opening the sealed HDD in a cleanroom environment.
Removing the platters and locking the actuator arm.
Desoldering and replacing the read/write head assembly.

Reassembling the drive with alignment checked electronically.
Testing and reconfiguring the drive electronically.

The exact tools and techniques vary between HDD models and manufacturers. Most importantly, the process must be performed with extreme care to avoid any contamination or mechanical shocks to the delicate platters and remaining heads.

Specialized equipment needed

Here are some of the specialized tools and equipment involved in HDD head replacement:

Cleanroom – An ISO Class 5 cleanroom or better is required to meet the strict anti-contamination requirements.
ESD equipment – Anti-static tools and wrist straps are needed to prevent electrostatic discharge damage.

Head tools – Specialized microscopes, tweezers, grippers, and suction cups are required for handling the tiny heads.
Opening tools – The HDD case has unique seam welds and adhesives that must be safely opened.
Head swap jigs – Jigs align and hold the actuator arm during head assembly swaps.

Spinstand – Used to electronically test drive function before reassembly.

Without this specialized equipment and skills, most head replacement attempts would quickly destroy the drive through contamination or mechanical damage. The cost of these tools is why HDD head replacement is limited to professional labs.

Are there any DIY techniques?

There are no practical DIY techniques for HDD head replacement. The amount of microscopic contamination control and precision required make a cleanroom and specialized tools mandatory. The only option for DIY head replacement would be an amateur cleanroom with improvised tools.

Some of the DIY techniques that could theoretically be attempted include:

Building a rudimentary cleanroom enclosure from plastic sheeting.
Using high magnification photography lenses as an improvised microscope.

Microsoldering and electronics work under a magnifier.
Trying to open the drive in a static controlled workspace.
Creating head swap jigs from machined plastic and metal.

However, the contamination risks and lack of precision from such improvised tools make successfully completing a head swap unlikely. The first speck of dust or slip of a tool would cause terminal damage to the drive platters or heads. Not to mention the advanced electronics work required.

Can a repair shop replace heads?

Yes, there are professional data recovery labs that can replace HDD heads. However, only a small number of specialized labs attempt this advanced technique. The skills and equipment needed narrow the field down significantly compared to general HDD repair.

Things to look for in a HDD head replacement service:

ISO Class 5 certified cleanroom on site.
Experience specifically with head replacements on exact drive models.
In-house platter imaging and head servicing capabilities.

Certified engineers and specialized tools.
Positive customer reviews for head recovery services.

The cost for head replacement services ranges from $800 to $2500+ depending on the drive. There is no guarantee of success, since contamination or other undetected damage may still prevent head replacement from working.

Should you attempt head replacement?

For the vast majority of users, attempting DIY HDD head replacement makes little sense vs just replacing the drive. The specialized equipment and skills required, along with the high risk of wrecking the drive in the process, are good reasons to avoid this advanced technique.

That said, if the data is invaluable and worth a try, seeking professional head replacement services can sometimes recover the data. Cost-benefit wise, HDD head replacement makes most sense for recovering data from expensive server drives or drives with truly irreplaceable data.

In summary:

HDD heads can technically be replaced in a professional cleanroom.
Specialized tools and skills are an absolute must for this delicate process.
DIY head replacement has almost no chance of success.

Leave it to reputable professional labs if the data is valuable enough.
For most users, replacing the failed drive is a better option.

Factors impacting head replacement success

If pursuing professional HDD head replacement, there are several key factors impacting the likelihood of success:

Contamination – Less dust exposure and fouling of the platters increases success chances.
Model familiarity – The lab must have specific experience with the exact HDD model.
Failure mode – Mechanical failures are better than electronic failures.

Platter damage – No scratches or bumps on platters makes success more likely.
Direction of swap – Swapping the actuator arm is better than just replacing heads.
Donor drives – Having an ideal donor drive makes head swaps simpler.

Specialized labs determine the viability for head replacement based on diagnostics of these factors. While the lab handles the actual process, being aware of these factors can set proper expectations of success.

What happens if head replacement fails?

There are a few potential outcomes if the head replacement attempt is ultimately unsuccessful:

Drive totally destroyed – A contamination breach or mechanical shock can completely kill the drive.

Original failure recurs – The replacement head fails just like the original.
Undetected platters damage – Hidden platter damage prevents head from working.
New failure mode appears – Something unrelated fails during reassembly.

In these cases, the data is likely unrecoverable even by a data recovery lab. The only hope may be platter transplant to a donor drive, but this has even lower success rates than head replacement. Unfortunately, failed head replacement means paying for the attempt with no better outcome.

Can heads be replaced with mismatched donor heads?

Ideally, the replacement heads would come from an exact matched donor drive to ensure compatibility. However, labs sometimes have success using mismatched donor heads in a swap.

Compatibility considerations when using mismatched donor heads:

Same head technology – e.g. GMR, TMR, PMR, etc.
Very similar or same aerial density and specs.
Electronics interfaces must match.

Mechanical fit and attachment points.
Platter surfaces must aerodynamically support heads.

There are always risks of incompatibility issues causing problems down the line even if mismatched heads work initially. The closer the donor match, the better the long-term viability of the head replacement.

Consequences of failed HDD head replacement

Once the decision is made to pursue professional head replacement, failure to recover the data can be an expensive lesson. Here are some of the consequences that can result:

Permanent data loss – The data may be unrecoverable by any means.
Wasted money – Payment for the attempted recovery yields no data.

Additional drive damage – HeadsSwap attempts can damage the platters.
Lost time – The process can tie up the drive for weeks before declaring failure.

To limit negative consequences, it helps to be selective about cases sent for head replacement. Choose drives where the data loss would have major impact and carefully vet the labs.

Can HDD heads be repaired or serviced?

Rather than a full head replacement, some labs attempt to repair or service malfunctioning heads. This includes techniques like:

Microsoldering electronics on heads.
Realigning or adjusting heads.

Cleaning and degaussing heads.
Repairing or replacing head suspension.
Servicing pivot bearings.

The feasibility of these depends on the failure mode and drive model. The main advantage over replacement is avoiding donor heads compatibility issues. But repairs still temporary fixes on used heads prone to future refailure.

How long does HDD head replacement take?

The overall head replacement process takes 1-2 weeks in a professional lab. Some of the factors impacting timeline:

Diagnostics to pinpoint failure mode – Up to several days.

Locating compatible donor drives – Could take days to source.
Schedule backlog at the lab – May wait days for next opening.
Actual cleanroom head swap procedure – Around 2-3 hours.

Testing and reconfiguring drive after replacement – 1-2 days.

Rush orders can sometimes be accommodated for critical recovery cases. But otherwise 1-2 weeks is typical turnaround. The data importance should outweigh the long wait.

Head replacement procedure step-by-step

While the exact techniques vary between drive models, this is a general overview of the head replacement process in a data recovery lab:

Diagnostics on drive to determine failure mode and viability.
Disassemble drive in cleanroom and expose internal components.
Lock actuator arm and carefully detach platter stack.

Remove existing heads with specialized microgrippers.
Clean and inspect platter surfaces under microscope.
Fetch and prepare the replacement heads from donor drive.

Precisely attach replacement heads to actuator arm.
Reassemble drive casing and reconnect electronics.
Electronically configure drive with new heads.

Run functional tests on spinstand.

This overview simplifies what is really a delicate microsurgery level procedure. Each step must be performed with absolute precision on micron scale components. But in general, this depicts the head replacement process flow.

Limitations of head replacements

While HDD head replacement can sometimes recover data, there are definite limitations and drawbacks vs just replacing the drive entirely:

Low success rate – Contamination risk is high.
No permanent fix – Used heads still fail eventually.
Specialized skills needed – Not DIY friendly.

Slow process – Takes days for diagnosis and swap.
Expensive – $1000+ with no guarantee.

Weighing these limitations against the chance and value of data recovery helps determine when head replacement is worth pursuing.

Future technologies and alternatives

Current HDD head replacement techniques are challenging, but future technologies could improve the process:

Advanced robotic handling – More precision using robotics.
Non-mechanical heads – Beam steering heads avoid crashes.

Contamination control – Next-gen cleanrooms and materials.
Diagnostic tools – Better viability detection prior to tear down.
Head refurbishment – Advanced servicing of used heads.

Research is ongoing into many of these areas. Alternative data recovery techniques are also being developed to handle cases beyond head replacement such as:

Platter transplant – Move platters to donor drive.
Flash recovery – Extract raw NAND chips.

Reconstruction – Rebuild data mathematically.

But for now, head replacement remains an option of last resort for irreplaceable HDD data recovery when performed by the right professional lab.

Conclusion

In summary, HDD head replacement is technically possible but realistically limited to professional cleanroom labs. The delicate and specialized work involved puts it out of reach for DIY attempts. Carefully vet labs advertising head replacement capability and understand the limitations before committing to this expensive process. For less valuable data, replacing a failed HDD is generally the more practical and cost-effective option vs risky head replacement attempts.