Has it been working in the past and just stopped - or is it a new self-install - if the latter did you call in to activate the Hub?
Firstly, check all your coax connections are in firmly - nice and "finger" tight at the Hub and wall box and at any inline splitters/attenuators/etc and with no “unterminated loose ends, and that the internal wiring is ok with no kinking or chaffing. Also check that all looks good with the outside cabling and wall box.
Then try this to see if it comes to life - worth a shot With the Hub "on" push in the pin on the back/side/bottom of the Hub with the end of a paperclip until you feel it at the “stop point” and hold it there firmly for a "timed" 60 seconds do NOT restart the Hub after that. Leave it 5' or so to stabilise and then your passwords/passphrase for both the Hub settings and the Wifi networks will revert to the two printed on the Hub sticker on its base/side/card.
If that doesn’t sort it - call it in as a fault.
-------------------- John --------------------
My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired 2 WiFi,) SH2 in modem mode with Airport Extreme Router. On VIVID200, Talk Anytime Phone, x2 Mobile SIM only iPhones.