So this might be worth noting / help somebody else, forward to earlier posts...
My broadband died earlier but I had all 4 lights green on the front of the BrightBox 2; whilst my devices were connecting to it OK, they all said 'connected, no internet'.
Land line was functioning properly.
After rebooting, checking master socket, external cable and whether any engineers were working on the local cabinet across the road from my house (they weren't), I rang 150.
After about a half hour of (successful) line tests, router factory resets and config restores, the rep asked for the router serial number, at which point she realised my broadband account still listed my original Bright Box 1 details and serial number. She refreshed these details and hey presto, broadband instantly back up and running.
Seems my Bright Box 2 was still listed against the original owner's account; all I can think is maybe EE systems automatically check the details on your account from time to time against those being reported by your hardware (presume they would need to do this for firmware updates, etc.) and may deny your service if there's a mismatch?
tl;dr, moral of the story: if you're going to use a 2nd hand EE router, might be worth giving EE tech support a call on 150 and giving them the router model and serial number to list against your account.
