Data Recovery Case File · NAS & External · Electrical Damage

WD My Cloud recovery: the wrong power supply, a 4TB Red that won't spin, and a board repair done properly

Barrel connectors are the quiet villain of home NAS storage: several sizes look interchangeable, and the adapters that fit are not the adapters that are safe. One wrong plug took out this single-bay My Cloud — and when the customer tried the bare drive in a USB caddy, it was silent there too. The fault had reached the drive itself.

The enquiry

“I accidentally plugged the wrong power supply into the NAS. I was hoping it was just the NAS controller that was dead, but I've tried the drive in an external caddy and it does not spin or power up at all. Could this be repaired by replacing the controller board on the drive?”

What a wrong adapter actually does

Hard drive PCBs carry sacrificial protection — TVS diodes designed to clamp an over-voltage event by failing into a short and taking the fuse or a trace with them. When the protection wins, the drive is completely dead but completely fine: replace or lift the failed protection component and it runs. When the surge is large or sustained enough, it gets past the sacrifice and into components that matter — the motor controller that drives the spindle, or the main controller itself. Diagnosis on this board showed the second, worse pattern: the protection had clamped but the spindle driver stage had been damaged before the event ended. The customer's caddy test was well-reasoned, and its result was accurate — this board was not going to spin a motor again.

The repair — and the chip that had to move

His proposed fix, "replace the controller board," was half of the correct answer. A matching donor PCB restores the electronics, but every WD board carries an 8-pin serial ROM holding that individual drive's unique adaptive data — calibration values measured against its specific heads and platters at the factory. A donor board running donor adaptives ranges from "drive undetected" to, in unlucky cases, heads flown at the wrong height over your data. So the original ROM was desoldered from the damaged board, transferred to the donor, and only then was power applied — current-limited, on the bench, watching the rails behave before the spindle was allowed to spin in anger.

The drive came up cleanly and identified with full capacity, and went directly onto the Atola Insight Forensic for a complete write-blocked image — a drive that has been through an electrical event gets imaged before anything is asked of it, however healthy it now sounds. The image completed without a single unstable region, confirming the surge had spent itself entirely in the electronics.

Getting the data out of a My Cloud's format

One step remains that catches people out. A My Cloud drive is not a Windows drive: inside is the NAS's own Linux system — several small firmware partitions and then the data volume in a Linux-native filesystem, which is why a My Cloud disk shows as unreadable when connected to a Windows PC even when perfectly healthy. Working from the image, the data partition was located and mounted, the share structure extracted, and the customer's file set — the usual full spread of family photographs, documents and a music collection — verified and delivered on a new external drive.

Outcome

Complete recovery. The honest classification: this was a wholly fixable fault handled before it became an unfixable one, and the customer contributed to that by stopping after one careful test rather than shopping the drive through a series of enclosures and adapters. Electrical cases reward restraint — every fresh power-up against damaged electronics is another roll of the dice.

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.