USB cable not supplying enough power for hard drive...

External portable hard drives are powered by a USB cable alone. As they spin much slower than 3.5 inch hard drives they do not consume as much power. If you have a faulty USB cable, you may notice that the drive clicks when you connect the power.

Clicking is normally associated with a head failure, but we are receiving many portable external hard drives that are completely healthy. Inadequate power being supplied to an external HDD is most common in situations especially where you have many data storage devices on a single USB hub.  Make sure you always check the USB cable before assuming you have a major hard drive problem! Often a USB cable longer than 18 inches or 22 inches for WD My Passport drives will simply not supply enough power from a USB port on a computer. You can buy a supplemental power booster cable, but not before you have tried other cables.

However if all these solutions fail - you may well be looking at a hard drive that has mechanically crashed. If so, you will need specialist knowledge to recover the data!