I have a kenwood audio-video surround receiver VR-517, I'm trying to hook my kenwood multiple cd player CD-404 into it, when I hook the cd player into the cd-dvd output in the rear, it doesn't play, but if I hook it into the aux it will play a cd, but when that cd ends it will not go to the next cd without the receiver jumping back to cd-aux and no sound coming out. Can you explain to me how to hook it up to cd and get sound? Thanks in advance