Flashing light

I have come home from holidays and when I powered up my hard drive the light continually is flashing and my computer is not picking it up.  I have treid rebooting the computer and turning the hard drive on and off.

Check the drive on a different computer or with a different USB cable.

For other suggestions, please see the link bellow:

WD external drive is not assigned a drive letter by Windows or Mac OSX and data on the drive is inaccessible