1. Look in modem ports is there are signal where is cable switched. If dont have signal 1 modem is gone.
2. On the modem is 2 ports. Use 1 cable and put 1 end in 1 port and another in 2. If both lamps lights then your modem is ok
3. Start-settings-network connections-right click local area network-properties-internet protocol-properties-obtain an IP adress automatically or call admin for appropriate IP settings
4. Same happens to me and works