Itunes will not recognize iPod

Hi,

Bought iPod off ebay and it did exactly what seller described: Itunes initially won't recognize it and when it finally does, it asks to restore, so I try and it goes through most of restore until error comes up that iPod is corrupt. I downloaded Itunes 9 to my pc and now Itunes will not recognize it at all. The computer itself finds it but I don't know what to do from there. I tried resetting the iPod and it still does the same thing. It looks to work just fine, menus and all on the device itself. Everything seems to be fine, although I did listen to it and there is a whining noise when I turn the iPod on. I've looked at many of the problems on this website to figure it out and am still not sure if it could be the harddrive or logic board. I tried all this on my pc and mac and same results. I looked at the repair guide for this iPod and figured I'd ask before attempting the hellacious task of opening it. I've already fixed two 5th gen iPods with this site and the results have been super! Any help or advice is greatly appreciated and will be well received.

Thanks all,