I mistakenly plugged my HP

Question

I mistakenly plugged my HP IPAQ power cord into my 500GB Buslink model UII-400 external hard drive; and must have blown something 'cos now as I plug in the right cord for the hard drive, it only blinks but never comes on like it used to. What should I do? I have loads of school work saved on this hard drive that I must access to finish my papers or risk failing!