Have you tried configuring the ADSL modem router for the internet connection?
Its possible that since you have changed the ADSL modem router, you may have to configure the ADSL modem router for it to work fine. The configuration depends on what Internet provider you have but you may try these steps for now:
1. Make sure the connections are correct. Connect the computer to the LAN port and the ADSL line to the port assigned for that behind the device.
2. Launch an Internet browser and access http://10.0.0.2
and press enter. If a dialog box appears, set the user name as admin and password as zoomadsl and press enter.
3. On the basic setup page of the ADSL router, set the appropriate encapsulation and other settings based on the settings of your provider. If you do not know the settings for your provider, there is a table specified on the user guide for the ADSL router. Here is the link: http://zoom.com/documentation/adsl/5590_UserGuide_EngD.pdf