My video input won't let me use the non HDMI video input

[Chris555]

Why would there be a standard yellow "video in" on my Sony 7.2 receiver, but no way to get it to recognize the signal coming from my DVD player and send it along with the optical sound to my tv.

 

[americanaudiophile]

Model numbers would help.
If you connect a source with composite video you might be able to change the audio input associated with that video input in the receiver input set up menu to optical but the default would be analog RCA inputs. The receiver would not send audio to your TV since it would assume that it would be providing audio not the TV.
Not all TVs will convert a composite video input to HDMI. If yours won't then you won't get a picture if the HDMI out of the receiver is the only connection to the TV.