What is the exact model of the external drive? For some reason I think I remember reading that a few WD externals use a proprietary HD connector internally to the housing.
Your options: If you are lucky, the housing/interface is toast and you can get a USB-hard drive adapter, or a docking port to recover files. Not so lucky, if the internal connector on the hard drive isn't a standard SATA, you will need to grab another external hard drive of the same model, and swap the hard drive in the housing. Really, really unlucky, the hard drive has sustained internal damage and will need to be sent to a professional recovery service.
You are kind of lucky as the hard drive isn't being seen at all. If it was seen, and you had read/write errors, then you could assume a damaged hard drive. The fact that nothing appears when it is hooked up gives me a little hope the housing itself, or the internal connections are damaged/loose.
Either way, first step, make sure it powers up. If it uses a regular USB cable, swap it out to verify the cable is OK, plug it into a different USB port also. (I am assuming it was plugged in to your system when it was knocked around). Sometimes ports and cables get damaged when they get yanked on. After that, grab a screwdriver, and whatever tamperproof bits you need to take the housing apart to inspect the internals, connectors and the hard drive itself.
After that, then further decisions can be made.
Edited by dpunisher, 15 August 2013 - 10:25 PM.
I am a retired Ford tech. Next to Fords, any computer is a piece of cake. (The cake, its not a lie)
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