What's the make and model of your EHDD? Is that the adapter that came with it or did you try to use one from another? Also, if you look at the drive you should be able to find the voltage rating, in/out, etc, you can then look for a new one based on that info.
Try using this as a goolge search: ac adapter 100-240 VAC, 50/60Hz, 2A
and see if that helps. You can try just a web search or click the shopping option.
What a world, what a world...