Look for a "reset" button on the face or on the front of the head unit with the face removed. It's usually a recessed button you can press with a pen tip. Some JVCs have it, most don't. If it doesn't have a reset button, try pulling the plug out of the back of the head unit for about a minute, then put it back in. If you can't access the back of the head unit very easily, disconnect your negative battery terminal for a minute. Resetting the head unit might get it to spit out the CD, or it might not, but it's worth a try.