The Optik boxes don't have a DVI connection. Something is weird with your TV. The RCA RHOS651SM is not supposed to even have a DVI port on it. It has a VGA port but the Optik box doesn't have that connection either. Most Optik boxes don't have HDMI-CEC support so they won't typically force the TV to change inputs when the box is turned on.
Go to your TV and change the input to the HDMI port the Optik box is connected to. The power button on the RCA RHOS651SM should double as the Input button. If that doesn't work, look for the input or source button on the remote that came with the TV itself.