From my experience HDMI connections are prone to move around- depending on how the cable is routed, especially.
Also, s-video cables don't have the most firm connection. They have a small "dimple" at twelve-oclock position (if I remember correctly) that provides the only "lock". Otherwise they can sometimes fall right out.
A forum community dedicated to home theater owners and enthusiasts. Come join the discussion about home audio/video, TVs, projectors, screens, receivers, speakers, projects, DIY’s, product reviews, accessories, classifieds, and more!