An external drive is a disk and a small translator board sharing one shell, and it is worth knowing which of the two has failed before anything else happens. This page separates them, explains the format prompt that should always be refused, and covers the one trap that ends recoveries outright: opening a WD My Passport or My Book and separating the disk from the board that holds its encryption key.
An external drive is a single disk: £300 + VAT, diagnosed free first. Send the whole unit in its enclosure — and on a WD My Passport or My Book send the cable too, because the encryption key lives on the bridge board rather than on the disk.
An external drive is two devices in one shell: a hard disk, and a small board that translates USB into something the disk understands. Half the faults on this page are the board rather than the disk, which is much better news than it feels like at the time.
The light comes on, you can feel it spinning, and no letter appears in Windows or Disk Utility. Check Disk Management or Disk Utility before assuming the worst: a disk visible there with no letter, or shown as RAW, is a filing fault on working hardware and the best position on this page.
Say no and unplug it. That prompt appears exactly when the structure recording where your files start has been damaged, and formatting writes a fresh one over it. The contents are almost always still present when the box appears. Every action after it decides how straightforward the recovery is.
The disk inside is mechanical and it is in trouble. Beeping usually means the motor is trying to spin against resistance; clicking means the heads cannot position themselves. Neither improves with a different cable or another go tomorrow. Power it off and leave it off.
No light, no spin, no vibration. Often the enclosure rather than the disk: a failed bridge board, a broken socket, a bad cable, or a mains adapter of the wrong voltage. That is a cheap fault wearing an expensive disguise, and the free diagnostic separates the two without you paying to find out.
Desktop 3.5in units are heavy and topple easily, and a running drive that falls tends to park its heads on the surface. If it has not been switched on since, do not check. If it has, say so honestly, because it changes what the bench expects and how the imaging is planned.
Weak sectors, an overheating bridge, or a bus-powered 2.5in drive on a port that cannot feed it. Retrying the copy is the worst available option because it makes a struggling disk work hard over the same difficult areas. Stop, and let it be imaged properly on equipment that expects the drop-outs.
The usual internet advice for an external drive that has stopped is to take it out of its case and connect it directly to a computer. On many units that is harmless. On a Western Digital My Passport or My Book it can be the end of the story, because those enclosures encrypt by default and the key material lives on the bridge board inside the case rather than on the disk. Separate the two and the disk becomes an unreadable block of ciphertext to everybody, including any laboratory in the world.
So for a WD unit, send the whole thing: the enclosure, the disk inside it, and the cable it came with. That is not packaging advice, it is the difference between a routine job and an impossible one. If somebody has already opened one and the board is still in the box, send the board too and say what happened.
The general shipping rule follows the same logic: an external drive travels in its own enclosure and a NAS travels whole, while a laptop, desktop, iMac or CCTV recorder sends its bare drive alone. RAID and server sets send member disks only, labelled with their bay order and with the chassis front photographed first.
The small bus-powered drives take their power from the USB port, so a port that cannot supply enough current produces symptoms that look exactly like a failing disk: spinning up and down, dropping out mid-copy, appearing and vanishing. Trying a rear socket on a desktop, or a powered hub, is one of the few free tests worth doing.
The larger desktop units have their own mains adapter, and that is where they go wrong. Using an adapter from a different device is a good way to put the wrong voltage through a board that was not expecting it, which takes out protection components and sometimes more. If a drive died the moment it was plugged in with a borrowed power supply, mention it, because it points straight at the electronics rather than the mechanics.
Many large consumer drives use a recording technique that overlaps their tracks to fit more on, which is fine for reading and for occasional writing and very slow when the drive is asked to sustain heavy work. Combine that with a few weak sectors and you get the familiar picture: a copy that starts at a reasonable speed, collapses to a crawl, and eventually stalls or disconnects. Repeating it is the natural response and the wrong one, since each attempt spends more of a failing disk's remaining working hours on ground you have already covered.
Do not run recovery software from the affected drive, and do not install it onto the machine's own disk if that is what you are trying to recover. Do not let anything write its findings back to the drive being read. Do not initialise, format, or accept a repair offer. And do not leave it plugged in while you think about it — a drive that is degrading gets worse whether or not anyone is using it, so the power is better off.
An external hard drive is a single disk, so it is £300 + VAT — the same as an internal one, whether the fault turns out to be the disk, the bridge board or the file system. Memory cards, USB sticks and pen drives are £250 + VAT. Recorder disks from CCTV systems and encrypted volumes where you can supply the key are £400 + VAT. NAS boxes, RAID arrays, SAN volumes and servers start at £500 + VAT and rise with the number of members. Forensic work is £800 + VAT with a written report, or £400 + VAT for a binary image with deleted-file extraction and no report.
The diagnostic costs nothing and closes two working days after the drive is booked in. The figure that follows it is fixed and in writing. Logical faults — RAW volumes, deleted files, damaged partitions, a failed bridge — carry no fix, no fee. Electronic failures, mechanical failures, chip-level work, DVR jobs and forensic jobs sit outside that guarantee, and physical work takes half the quoted figure upfront.
Externals are easy to post because they arrive as one object. Wrap it so nothing moves in the box, include the cable if it is a WD unit or if the power supply is unusual, and put a note in with a name, a number you answer and a line about how it failed. Royal Mail Special Delivery is tracked and insured and is what most people use.
Or bring it: Compass House, Vision Park, Chivers Way, Cambridge CB24 9AD, drop-offs Mon–Fri 9:00am–5:30pm, about 70 miles from Leicester down the M1 to J19 and east on the A14, two minutes off Junction 32 with parking outside. There is no Leicester counter and nobody collects.
Recovered data is returned on separate media, with a file list to check against what you were expecting. The failed drive is returned too if you want it, though it should be treated as finished rather than reused — a disk that has needed a laboratory once has told you what it thinks of your data.
The uncomfortable question worth asking afterwards: why was this the only copy. Externals fill that role in most households by accident rather than decision, and the cheapest hour anybody spends is the one that puts a second copy somewhere else.
Roughly half of these turn out to be a bridge board, a socket or a power adapter, and the diagnostic that proves it costs nothing.
A padded box and a tracked label do more for a struggling disk than any amount of driving around with it. Royal Mail Special Delivery handed over in Leicester in the afternoon is generally on the Cambridge bench the following working morning, which is faster than most people manage in person.
The general rule is the drive travels and the machine stays behind — out of the laptop, out of the tower, out of the iMac, out of the recorder under the counter. This bench does not dismantle equipment, and a repair shop will do it while you wait. Three things are the other way round, and getting them wrong costs you the recovery: an external drive stays sealed in its own case, a NAS comes as a complete unit, and a WD My Passport or My Book travels whole with its cable, because on those the encryption key is held on the bridge board rather than on the disk — separate the two and the data becomes unreadable even to us. A Fusion Mac needs both of its drives, each labelled. The one thing nobody can work round is flash soldered onto the mainboard, as on Apple Silicon machines: if it will not come off, there is nothing to post.
↓ Print the shipping & booking-in form (PDF)
Address it to Cambridge Data Recovery. It is about seventy miles from Leicester if you fancy driving it — M1 south to Junction 19, then the A14 east — and the lab is two minutes off Junction 32 with parking at the door. Posting costs you a stamp and a day instead. Whichever you choose, you hear from us the moment it is booked in, and the free diagnostic closes two working days after that.
Not certain what belongs in the box? Ring 0800 689 0668 before you tape it up, or let the free online diagnostic ask the questions for you.