Sounds like something I just had happen a couple weeks ago. If it is, there's a tutorial on how to try and correct the problem. The model of my Seagate HDD was different from the one shown, but after following the steps, it worked perfectly. The drive became operational and all my data was/is still intact. Though, I may have just been one of the lucky ones.
Here's the exact USB Cable
Free version of HyperTerminal P.E. 6.3
Now, my cable didn't turn out as "pretty" as some examples in the thread, but it certainly did the job.
*edit - Here's a youtube video
that also helped me out, in case you wanted to see the process in action.