The DV and HDV firewire are separated on these cameras.
The DV side can be functioning whilst the HDV is faulty.
You could try downloading the demo version of Veescope Live and connecting your camera that way.
http://www.dvdxdv.com/NewFolderLookSite/VeeScope/Products/VeescopeLive.over...
It's a useful program that allows you to record .mov direct to your laptop. If it works in DV and not in HDV you have isolated your problem. It's costly fix if the HDV firewire is faulty.
Cinematographer, Steadicam Operator, Final Cut Pro Post Production.
http://www.steadi-onfilms.com.au/