There are 4 status that lights indicates : Power - ADSL - Internet - LAN. On powering up first the modem/router, the first light is on the power. If there is a connected PC on wired from end to end, then the LAN will lit. While ADSL blinks to load for a minute or so, then establishes a connection, the Internet lits up last. Now if the ADSL light goes off intermittently, I would suggest calling your ISP first.