I have a DCT700 cable box which is connected by RCA composite video/stereo audio to my Yamaha RX-V575 receiver (AV6 connection). It outputs to my TV through HDMI and the audio goes to two bookshelf speakers. The audio from the cable box comes through fine but all I get for video is a blank black screen. I tried it out using coax to go directly to my TV and that worked, so it must have something to do with my receiver or the composite output versus coax? I can't test composite going directly to my TV as it doesn't have any composite video inputs.
Not sure what else I should attempt here.