Cannot access data on my external hard drive – what to do?

External hard drives have become part of our lives – we use them both for backup of our important data, say photos from family archives, and as a convenient portable storage, for example for favorite movies and TV series.

However, the main advantage of such storage devices – portability – is also a major weak point. Such devices often fall, breaking USB connection. They are also subject to filesystem failures associated with connection-and-removal cycle. All these things potentially lead to data loss – in the best case you just cannot get access to the data on the drive, in the worst case your data is actually lost.

In the post, I consider a case when for some reason you cannot get access to the data on your external hard drive. The problem appears when you connect the drive to a PC as you typically do, but nothing happens – there is no error message and no drive letter appears in My Computer and in Disk Management.

The possible reasons of such a failure are:

  • USB box failure,
  • mechanical failure of the disk .

In any case, the first thing to do is to remove the USB case and connect the disk to a PC. The most recommended method is to connect the disk directly to a motherboard using a SATA cable. However, this process may be tedious because you need to disassemble your desktop, locate a free SATA port on the motherboard, and a free power cable from the PSU unit.

Read alsoExternal USB SATA Drive Dock – Now You Can Make Use Of All Your Extra Hard Drives Easily

As an alternative, you can choose another way, simpler and faster, and connect the disk to a PC using another USB-to-SATA adapter. Choosing this road, you sacrifice to speed and stability.

Whichever you choose, never try to open the hard drive itself. The modern hard drive does not have anything inside which can be repaired without equipment.

So let’s start to disassemble the case to remove the USB box. Note that external drives are not designed to be opened meaning that opening may void the warranty – keep this in mind. One more note is that due to the variety of vendors and models the ways to open external boxes may differ – consider searching for a video instruction for your particular model.

I have a Transcend external hard drive.

Transcend external hard drive

The first step is to remove a rubber cover.

remove a rubber cover

Then take a screwdriver to remove three screws holding the halves of the case together.

remove three screws

Now it’s time to open the box to extract the disk. Take some sharp and flat tool like a knife, flat-blade screwdriver or a special tool like mine (blue stick on the photo), insert the tool in the gap between the two halves, and split them out.

open the box to extract the disk

Take off one more rubber shell.

Take off one more rubber shell

At this stage, no matter what box you deal with you will see the disk itself.

We see that there is a USB-to-SATA controller connected to the SATA port of the disk. We need to remove it so that SATA port on the drive becomes accessible.

USB-to-SATA controller

Also you need to remove any extra bits which may be still attached to the drive; the Transcend drive I chose as an example has some sort of metallic plate bolted onto the drive, probably to provide better grounding and also some shock resistance. This plate has to be unscrewed and removed, so it does not prevent fitting the bulky USB-to-SATA adapter.

USB-to-SATA adapter

Next, we connect the drive to a PC using a USB-to-SATA adapter. Such an adapter is a very useful thing and typically, you can buy it in any electronic store for $10-20. The only advice here is to choose a USB 3.0 adapter having its own power supply.

Connect the adapter – SATA and power connections.

SATA and power connections

No matter what the adapter manual says about power connection, always connect power because a rotational hard drive requires much power when starting.

Now connect the set to the USB port of the PC and power it up.

USB port of the PC and power it up

It is important to keep the disk away from contacting with surfaces. This is what sheet of paper is for. Not only does it provide a white background for the photo, it also prevents hard drive circuit board from contacting any possible metallic objects. Generally, once you connect the disk you should get access to the data immediately. If it is so, your original USB box is broken – buy a new external hard drive and copy the data to it.

If you have done all the above but instead getting access to the data you see a message asking you to format the drive, then in addition to the box failure you have some problems with the disk file system, so called RAW file system issue.

RAW file system issue

Never format the drive because formatting erases all the data from the disk. In this case, you should use special software designed to recover data from RAW file system.

The last and the worst possibility is when after doing all the above you still neither see your drive nor get any messages about it. Most likely, you deal with a mechanically damaged disk. In this case, you need either accept the data loss or contact a repair lab.

You should also be aware that some external hard drives, notably WD My Passport series, have a USB-to-SATA controller built into the drive. When you open the box, there is no SATA port on the drive. This type of the controller cannot really be fixed at home by simple means. For these drives, the only option is to contact a repair lab.