[tbcengineer]

I tried everything you have tried, then I finally out of desperation pulled the battery and sprayed some electronics contact cleaner directly into the usb port from the bottom of my Titan. Nothin' immediately improved (after blowing it dry for 10 minutes), but the next day it worked flawlessly and has since, including booting beyond the boot screen without the usb cable plugged in, sync'ing, etc.

Hope this helps.