antminer cant connect to pool?

[humma78]

Hi I received my first Mining machine and have been through the setup. Once it was connected it began mining fine to the default pool set up from the manufacturer, However once I deleted these and entered my own BTCguild details the miner hasn't done anything the green lights have gone off on the PCB and miner status details are totally blank. Can someone please help me get it going. Thanks.

edit: How can I tell if my machine can 'see' the internet?