We have several of these phones in our office. Before our move they were all setup with a different provider. Since the move we have change our provider to ringcentral.com. I see they provide all of the information for sip domain, outbound proxy etc...for the phones to be setup.
I started with my first one this morning, I reset it with the 123456789*0# command and now it appears to be stuck in a loop where it comes on says it's upgrading for a minute or two then goes to a Cisco splash screen for a minute then blank screen and repeats. Any ideas on how to get the phone to boot so I can enter in the new settings and get the phones back online?