I turned on Chromecast this morning and it immediately starting updating ... when finished it just sat there with the white light flashing. After 10 minutes I restarted the TV and the device, got the 'starting chrome' screen with the whirly circle, then blank screen!!
Tried factory reset using button, same result .... device shows up on router as a connected device.
Tried using laptop to access Set-up and it first said something about an 'unauthenticated device', then 'cannot access page'.
A quick Google search shows heaps of people in the USA suffering same problem.