If you really can't find anything from troubleshooting guide. Call the service helpdesk, they should give you some help.
Normally, cable service is DHCP enabled. if you still using the same network adaptor with the same MAC address( normally you won't change that). You should be able to connect after the system restart or re-installed.
It seems your network apaptor is not working, only the IEEE1394 port is enabled.