When you say it will not turn on do you mean that it does not completely boot up or it only goes to the splash screen?

I hooked mine up last night and it does the same thing. I think this is the way it works. When I plug the 660 to PC the splash screen comes on but that is as far as it goes. I went to the Garmin web site and looked for updates and it installed the software needed to check for updates. It found the 660 serial number and what updates were available. Note you have to register the unit within 60 days and only get one free update within that 60 days.

The battery does need to be in place or you get the error message.

Good luck and enjoy your new ride!