mike_forum, please do the following, but stop when something doesn't work as expected and report results.
1. Your router has four indicators on the front panel, labeled 1 ... 4. These correspond to the four gray ports on the back. When you plug the OBi into one of those ports, the corresponding indicator should light up. If it doesn't, try resetting the OBi to factory settings with a paper clip, as detailed by RonR. If that doesn't help, and you are sure that the Ethernet cable from the OBi is ok, the OBi is probably defective.
2. Pick up phone attached to OBi and dial ***4. You should hear the current IP address (192.168.0.120) and then be offered some options. Press 1 to enter a new value, then press 192*168*2*120#. When prompted, press 1 to confirm/save. Hang up phone and wait 30 seconds. Pick up phone and dial ***1. You should hear the new IP address (192.168.2.120). If not, stop and post what happened.
3. From a command prompt on your PC, can you ping 192.168.2.120 ? If so, proceed now to step 4. If not, can you ping 192.168.2.1 ? If not, stop and post. Pick up phone and dial ***0. Enter option 27#. If the value read back is 1, stop and post. Otherwise, press 1 to set a new value, press 1#, press 1 to confirm/save. Try pinging 192.168.2.120 again. If it fails, stop and post.
4. Open your browser and type 192.168.2.120 in the address bar. If you cannot access the page, stop and report what error is given. Otherwise, log into the OBi.
5. Navigate to System Management->Network Settings. Uncheck all the Default boxes under Internet Settings. Enter these values (some may already be set as below):
AddressingType: Static
IPAddress: 192.168.2.120
SubnetMask: 255.255.255.0
DefaultGateway: 192.168.2.1
DNSServer1: 8.8.8.8
DNSServer2: 4.2.2.2
Click Submit. When "reboot required" appears, click the Reboot button.
6. Test OBi by dialing **9 222 222 222.