Data Recovery Case File · Formatted & Logical Faults · A Control in the Same Machine
A Second Drive Working in the Same Host Removes Every Explanation Except the Drive
His enquiry contains a comparison most enquiries cannot offer. An internal drive not detected at start-up in a laptop that "has two drives, the other being solid-state, and this is being detected fine." The working drive is a control: same machine, same power supply, same firmware, same start-up sequence — so everything they share is eliminated, and only what differs remains.
| Media | Internal hard drive not detected at host start-up, in a machine also containing a solid-state drive which enumerates normally |
| Reported situation | Laptop containing two internal drives · hard drive not detected during start-up · solid-state drive in the same machine detected normally · machine otherwise operating · recovery of content from the undetected drive sought |
| Fault class | Single-device non-enumeration with the host eliminated by an internal control — board, firmware-stage or mechanical cause confined to the affected drive |
| Equipment used | Second drive treated as an internal control eliminating host-side causes · drive removed and assessed independently on a controlled bench supply · current draw measured across the start-up cycle · service area read under strict timeouts · imaged write-blocked once enumeration was achieved |
The decode: what the working drive rules out, and what it leaves
Why a second working device is so useful: it shares almost everything with the failed one. The same power supply, the same controller, the same firmware and the same start-up routine — and it works.
What that eliminates in one observation: the entire host. A machine that detects one drive is detecting drives, so the supply, the interface and the firmware's ability to enumerate storage are all demonstrated rather than assumed.
Why that is worth more than testing on another computer: a second machine introduces new variables. A control inside the same machine holds every variable constant except the drive itself, which is a cleaner comparison than any external test.
What remains after that elimination: the drive. Board, firmware-stage and mechanical causes are the three that survive, and nothing about the host contributes to any of them.
Why the machine still working is also practically helpful: he has a functioning computer. Nothing needs to be repaired to reach the content, and the drive can simply be removed.
Why removal is the right next step rather than further testing: the useful information from the host has been obtained. Repeated start-up attempts on a drive that may be mechanically faulty are the expensive way to learn nothing new.
What the drive's own behaviour will establish next: whether it draws normally, spins, and completes its initialisation. Those are measured on a controlled supply rather than inferred from whether a computer lists it.
Why the distinction matters for cost: a board fault is component-level repair with no donor parts and no opening. A mechanical fault is an entirely different job, and the two are separated in minutes.
Why the solid-state drive being fine says nothing about prospects: the two devices are unrelated in construction and failure mode. It is a control for the host and not evidence about the drive.
What is worth checking on the working drive incidentally: whether anything was synchronised or copied to it. A second drive in the same machine is a common place for a duplicate to exist, and it costs nothing to look.
On the bench
The second drive was treated as an internal control eliminating host-side causes — sharing power supply, controller, firmware and start-up routine with the affected device, so a machine detecting one drive demonstrates supply, interface and enumeration capability rather than leaving them assumed. A control within the same machine holds every variable constant except the drive, which is cleaner than testing on a second computer. Draw was measured across the start-up cycle.
The outcome
The second drive treated as an internal control, the affected drive removed and assessed independently, and draw measured across the start-up cycle. Free assessment, one fixed written figure including VAT; where a drive has to be opened, 50% of parts and labour is payable upfront with the balance only on success — otherwise no recovery, no fee. The decode: the working drive is a better test than another computer. It shares the supply, the controller and the firmware — so everything they have in common is eliminated, and only the drive remains.
When one of two drives in a machine still works
Mention it, because it's the most useful test you have — a second drive in the same machine shares the power supply, the controller, the firmware and the start-up routine, so its working eliminates the entire host in one observation. That's cleaner than trying the failed drive in another computer, which introduces new variables rather than removing them. Stop attempting to start it now and have the drive removed instead. And check the working drive while you're there, since it's a common place for a duplicate to exist.
That eliminates the machine — call Manchester Data Recovery on 0161 871 0788; the working drive treated as an internal control, the affected drive assessed independently, draw measured across the start-up cycle.
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Our case files are drawn from genuine enquiries received by our laboratory over the past ten years, anonymised to protect client confidentiality. Each one describes the diagnostic and recovery procedure our engineers apply to that fault, using the equipment listed.