Test the lan side first by disconnecting your dsl modem
reset the router again for good measure
connect an ethernet cable between your PC network card and the lan side of the router
wait a bit and it should get an IP address from the router
open a web browser and point to the IP of the router (192.168.0.1), see if you can log in.
If you cannot get to this point there is a configuration problem (PC, router) or hardware problem.
If you can log in then go to the status screens at note the WAN side information.
From here you are now troubleshooting the WAN side but this all depends on how your ISP
has you configured. You could have a static IP, could be dynamic, you might have a basic modem
where the router uses PPPoE to force a connection, or you might have an advanced modem with
built in routing and dhcp. IF you are not sure then your ISP will have this info.
However the most common connection is dynamic, which the 615 defaults to when you reset it.
Then its just a matter of connection your modem to the wan (internet) port using an ethernet cable,
waiting a bit then checking the status again to see if the IP, MASK, gateway, etc are populated.