If I call support about my hardrive will they be able to see my private documents?

Not able to see your private documents.

no-  that doesn't work.  the HDD can not be accessed remotely if you can not get into it locally.  and, of course, if you send it in for repair somewhere, they CAN see whatever it is in your files that you want to hide.  shall we speculate on what you're trying to hide?  my guess -- that something is quite common and repair techs do not care any more to look

Did you try connecting the portable drive to another computer? If it still does not work, your next step should be to bring the drive to a service center. No way I can see that being fixed through the internet. So yes, they can see the contents if ever but why should they even bother? Anyway, if you have private stuff in there that gets leaked out, you can always sue them, right?

Are these "private documents" things that you would be ashamed of, if someone else actually saw them, or got hold of them?   If so, you might want to ask yourself why you are keeping such documents on your system... (Please keep that in mind for next time!)    But for now, good luck in getting your hard-drive fixed. Hopefully it won't be too difficult to get it going again... 

if you are still under warranty, they will want you to send them the drive.

it's probably easier just to disassemble it yourself and connect it to a computer (internally, NOT thru USB) to fix it that way. 90% of the time this has worked for me. then i can put it back in the external enclosure and use it as normal.

No, my friend.  They use the serial number to ensure that you are the original purchaser of that hard disk drive.

i would hope not