You must charge device first (just connect switched off device to charger, and leave it connected for several hours).
Then - don't switch it on - connect device via USB cable to PC. Only now switch on your 700. If USB-cable/cradle in order, then 700 will start with TT-logo and 'drums', and immediately will connect to PC (logo with 700 connected via USB-cable will appear on 700 display).
PS Just my 700 behaves similar if not charged properly (flat battery) - just tries to start with logo, then loops. But after charging - recovers to connection to PC.