Please make sure the modem is connected to power and coax line firmly and also confirm with your internet service provider whether the modem is activated successfully and If your modem activated still no internet please perform hard reset on the modem then check internet on direct connection. Please follow the steps mentioned on below article on the device connected to modem without coax cable.

http://arris.force.com/consumers/articles/General_FAQs/SB6190-Factory-Reset

After the “Factory Reset “ were you able to connect to internet ? As this is a cable modem SB6190 Docsis 3.0 all the 4 LED lights need to be solid (Power/Receive/Send and Online ) so, connect directly the modem to an ethernet port computer /laptop to check on the internet .