I have a 2920n, earlier I accidentally clicked on the 'Service Activation Wizard' button in the web control panel and it started trying to connect, I immediately clicked cancel and carried on. Then around 5 minutes later the router locked up. I could not access the web control panel anymore or the LAN so I had to do a hard reset.
After doing this everything looked as though it was fine, I could access the control panel and it showed the internet connection as being active, but I could not access any sites or ping them, LAN access was fine. I could not work out what was wrong and I had my boss breathing down my neck asking why the Internet wasn't working, I did not know what to tell him because as far as I could see everything should be working.
After 5 minutes of continual hard reboots, factory resets and re-configurations the router still would not allow any Internet access...I gave up and went to fetch an old trusty router and began to configure that, and just as I had finished the 2920n suddenly allowed Internet again...
Something is obviously wrong with the 2920n firmware here, this button should not be in such a prominent position and definitely should not cause this behaviour!