1. Test every cable in the system directly to the TV. This includes the cable from the DVD player to the receiver as well as the cable from the receiver to the TV. Test both of them, make sure BOTH of them work.
2. If both cables work, you are feeding composite video using the monitor output composite video feed. Try connecting the DVD player to a different input to see if it is the DVD input that is bad. Make 100% sure you are connecting the YELLOW composite video cable from the DVD player to the INPUT of the receiver.
3. Make sure there is not a switch on the back of the DVD player that says 'PROGRESSIVE SCAN ON' and that it is not turned on.
4. Your TV doesn't have component video inputs (red/green/blue rca type connections)?
5. Return receiver, get a non-Sony product. It is pretty well established that Sony receivers are sub-par.