What causes a broken hard drive?

A hard drive failure can happen for a variety of reasons. Hard drives store all of your computer’s data and allow you to save and access files. When a hard drive stops working properly, you can no longer access the files stored on it. This can lead to data loss and system crashes. Understanding what causes hard drives to fail can help you prevent failure and recover lost data when problems do occur.

Physical Damage

Physical damage is one of the most common reasons for hard drive failure. The hard drive contains sensitive components that can be damaged by impacts, drops, vibrations, and other forms of physical stress.


Dropping a computer or external hard drive can damage the platters and heads inside the hard drive. The platters are thin, circular plates made of glass or aluminum that store data magnetically. The read/write heads float just above the platters on a cushion of air and move to different positions to access data. If a hard drive experiences a physical impact, the heads can crash into the platters, scratching their surfaces and destroying data. Even small vibrations from placing a computer on a desk too hard can sometimes cause head crashes.


Falling from heights onto hard surfaces will also usually damage hard drives. The sudden deceleration from the impact can knock the heads into the platters. Portable external hard drives are especially prone to drop damage since their small size makes them easy to knock off tables. Dropping laptops can also harm internal hard drives.


Vibrations from sources like loud speakers, motors, and driving on rough roads can damage hard drives over time. The repetitive motion can knock the heads off track or cause them to intermittently touch the platters. This gradually degrades the magnetic surfaces until data loss occurs. Hard drives are designed to withstand some vibration, but excessive, prolonged vibration exceeds the design limits.

Opening the Enclosure

Opening the sealed hard drive enclosure instantly exposes the platters and heads to dust particles. Even a small amount of dust can render a hard drive unusable once the enclosure is resealed. Filtered, positive air pressure keeps contaminants out of a sealed hard drive. Also, the slightest touch of the platter surface with a finger can leave oils and other residues that lead to head crashes and data loss.

Electrical Failures

Hard drives also contain complex electronic components that can malfunction and cause failure.

Power Surges

Sudden power spikes from sources like lightning, faulty wiring, or just turning equipment on and off can damage hard drive electronics. Voltage above the tolerances of the electronics can permanently damage control boards, chipsets, and firmware. A severely damaged control board can prevent the drive from powering on or communicating with the computer.

Controller Malfunction

The primary controller chip coordinates all the activities on the hard drive like spinning up the platters, moving the heads, and transferring data. If this chip experiences problems, the drive will not function properly. The controller may become corrupted and send bad commands to the rest of the hardware. Or its circuitry could simply stop working.

Motor Failure

Electric motors spin the hard drive platters at thousands of revolutions per minute. Motor malfunction is another cause of hard drive failure. Motors can seize up and stop spinning entirely due to bad bearings, burnt out windings, failed drive chips, or other factors. A non-rotating platter will prevent data access.

Head Actuator Failure

The head actuator arm mechanically moves the read/write heads across the platters as needed to access data. Problems with the coil and magnets that control the actuator can cause it to stop working, preventing access to some or all data on the drive.

Firmware Corruption

Firmware is low-level software stored in chips on the hard drive’s controller board. It gives instructions to the hardware and optimizes performance. If the firmware becomes corrupted or damaged, the hard drive may not function properly or at all.

Bad Updates

New firmware updates can sometimes contain bugs or compatibility issues that affect certain hard drives. Updating the firmware on an incompatible hard drive model can corrupt the firmware and lead to unpredictable behaviors like frequent freezing or the drive not appearing in the BIOS.

Electrical Damage

Power surges or voltage spikes can override, erase, or corrupt the firmware stored on the chips. Permanent electrical damage to the chips and data pathways can render firmware unreadable and unusable. The drive will not be able to load corrupted firmware when powered on.

platters. Computer use also generates heat inside the hard drive enclosure. Excessive heat causes platters to expand and hardware to overheat. If internal temperatures exceed specifications, components can become damaged or wear out faster. For example, consistently high temperatures can cause platter warping, motor burnout, and premature failure of the head actuator or bearings.

Temperature Effect on Hard Drive
Above 70°C (158°F) Increased risk of immediate failure
50-70°C (122-158°F) Reduced hardware lifespan over time
40-50°C (104-122°F) Optimal operating temperature range

Insufficient Cooling

Hard drives generate a lot of heat that needs dissipating. Laptop drives are especially prone to overheating due to their compact size and proximity to other heat-producing components. Using laptops on soft surfaces like beds can block ventilation intakes and cause overheating. Similarly, insufficient airflow and accumulated dust in desktop computer cases leads to heat buildup near hard drives.

Logical Failures and Bad Sectors

Logical failures occur when the hard drive hardware is in normal working order, but data content and access get disrupted. Causes include file system corruption, bad sectors, and accidental erasure. The physical components remain undamaged, but software and data problems render storage unreliable.

File System Errors

The file system manages the logical storage of data on the drive. It keeps track of where files are located and their names. If the file system becomes corrupted, the drive may experience catastrophic failures like the operating system not booting, or more subtle problems like being unable to open or save files. Common causes include accidental formatting, damaged partition tables, and bad sectors where file system data is stored.

Bad Sectors

Bad sectors occur when areas of the platter surface become unreadable by the heads. Causes include physical damage, manufacturing defects, and gradual magnetic decay over time. The drive reallocates data to spare sectors when possible to compensate. But extensive bad sectors eventually lead to irrecoverable read/write errors. Data recovery software can sometimes read around bad sectors and recover files.

Accidental Erasure

Accidentally deleting important files or formatting the hard drive can lead to logical failures. The drive functions normally, but critical user data gets removed. This is often fixable with data recovery tools if drive sectors have not been overwritten yet with new data. Best practices like backups and drive imaging can prevent file loss from accidental erasure.

Manufacturing Defects

Quality control problems during manufacturing can lead to hard drive failures shortly after purchase.


Dust particles that infiltrate the drive assembly weaken the air filter over time. This provides an entry point for more contaminants that can crash heads into platters. Even microscopic particles degrade drive reliability if introduced during manufacturing.

Parts Defects

Tiny imperfections in head suspension mechanisms can allow heads to stray off track. Low precision in the platter cutting process also contributes to read/write errors. Bad drive bearings increase friction, produce excess heat, and fail prematurely. Any substandard components can compromise hard drive lifespan and performance.

Assembly Issues

If assembly technicians don’t follow strict protocols, they can accidentally damage hard drive components during construction. Mishandling can stress the delicate internal parts beyond engineering tolerances or impair normal operation. Improperly assembled hard drives often fail shortly after use when components shift from their optimal positions.

Prevention and Failure Warning Signs

You can avoid many hard drive problems by handling drives carefully, using surge protectors, monitoring drive health, and backing up regularly.

Physical Damage Prevention

– Cushion laptops when transporting them to prevent drops and impacts.
– Keep computers away from vibration sources like speakers.
– Do not open the hard drive enclosure or touchplatters.

Electrical Protection

– Use an uninterruptible power supply (UPS) to regulate voltage.
– Plug computers into surge-protecting power strips.
– Prevent power cables from being accidentally unplugged.

Cooling and Maintenance

– Open up desktop PC cases yearly to clear out dust buildup.
– Do not block laptop air vents or use on soft surfaces.
– Replace old hard drives before age degrades their hardware.

Warning Signs of Failure

– Strange noises like grinding or clicking sounds.
– OS freezes, crashes, or failure to boot.
– Slow performance and long read/write times.
– Disappearing files and folder access issues.
– “Bad sector” and I/O error warning messages.

Catching problems early allows you to backup data and replace failing drives before catastrophic loss occurs. Monitoring tools like S.M.A.R.T. diagnostics and disk utilities can also detect problems developing on a drive.

Data Recovery

Data recovery services are often able to retrieve data off failed drives as long as the platters remain intact. Specialized techniques like disk imaging, platter transplants, and clean room data recovery can rescue data from drives that won’t power on normally.

Logical Recovery

If the hardware still functions, data recovery software can read around bad sectors, rebuild file system tables, and undelete accidentally erased files. Logical recovery works on simple software-level failures.

Mechanical Repair

For physical problems like head crashes and motor failure, technicians can transplant components between identical drives to get the platters spinning and heads positioned again. Then they attempt to image the drive before the repairs fail.

Clean Room Recovery

In a dust-free clean room environment, experts dismantle the hard drive and access the platters directly. They use specialty equipment to read data off the platters and image the drive. This is the most successful method for recovering data from severely damaged drives.


Hard drives can fail due to many different factors ranging from physical shocks to bad firmware. Following best practices like cooling, backups, and surge protection helps mitigate some failure causes. If a drive does fail, acting quickly to have a specialist perform data recovery is key to salvaging your lost files. Understanding the root causes of hard drive failure helps you take preventative steps and make smart data recovery decisions when problems occur. With proper precautions, you can minimize and recover from most hard drive failures.