Almost every fault falls into one of four categories, and knowing which you have determines everything — whether to keep the drive powered, whether software can help, and what a recovery will involve.
Mechanical faults get worse every second the drive is powered. Logical faults do not. Treating one like the other is how recoverable data gets lost.
The moving parts. Head-stack failure produces the familiar rhythmic click as the heads fail to find servo data. A head crash — heads contacting the platter, usually after a knock while spinning — produces scraping or grinding and causes permanent, cumulative surface damage. A seized spindle motor or stiction gives a buzz or whine with no spin-up.
These are the urgent ones. Damage accumulates with every rotation, so a drive that clicks should be powered down immediately and not tested. Recovery means clean-air work: donor heads, a motor or platter transplant, then imaging in short controlled passes.
The printed circuit board can fail from a power surge, a failed component, or simply age. Symptoms are silence: no spin, no lights, nothing detected. Sometimes there is a visible burn mark or a smell.
Board faults are among the more recoverable, with one catch — a modern drive’s board carries adaptive data unique to that specific drive, held in a ROM chip. A donor board alone will not work; the original ROM must be transferred across. This is why swapping boards at home, a piece of advice that circulated widely a decade ago, generally fails now and can make things worse.
Every drive holds firmware modules in a reserved service area on the platters. When a module becomes unreadable, the drive spins up perfectly and sounds entirely healthy but cannot present itself — it reports no capacity, a blank model string, or a size that makes no sense. Seagate drives are particularly associated with this pattern, though every manufacturer has its own version.
The good news is that the user data is untouched. Recovery means repairing or substituting the affected modules through the drive’s diagnostic interface until it enumerates correctly, then imaging it. Repeated power-cycling while troubleshooting is the main risk.
No hardware fault at all: a deleted file, a corrupt partition table, a formatted volume, a damaged file system, a failed update. The drive is healthy and the structures describing where things live are not. This is the only category where software is appropriate, and where time pressure comes from the risk of overwriting rather than from the drive deteriorating.
Whichever category you have, a single drive is from £300 +VAT after a free 48-hour diagnostic and a written quote — and the diagnostic exists precisely to tell you which of the four you are dealing with before you spend anything.
Four: mechanical (heads, motor, platters), electronic (the circuit board), firmware (the drive’s own service-area code), and logical (deleted files, corrupt partitions, damaged file systems). The first three are hardware; only the last is something software can address.
Listen to it. Clicking or ticking means the heads cannot find servo data; grinding or scraping means they are contacting the platter; a buzz with no spin-up means the motor. Any of these is mechanical, gets worse with every second of power, and needs the drive switched off now.
Usually, yes — board faults are among the more recoverable. The catch is that modern boards carry adaptive data unique to that drive in a ROM chip, so a donor board alone will not work; the original ROM has to be transferred. Swapping boards at home generally fails for this reason.
That is a firmware fault. The drive loads its operating code from a reserved service area, and if a module is unreadable it cannot describe itself properly — so it reports no capacity or a nonsensical one while sounding perfectly healthy. The user data is generally untouched.
A single hard drive is from £300 plus VAT, fixed in a written quote after a free 48-hour diagnostic that establishes which type of failure you have. Most jobs are no fix, no fee; clean-air and donor work carries a 50% deposit with the balance due only on success.