My POD is in storage so I can't review the set up, however, it really should be as easy as loading a DVD. Once you have confirmed the Jensen is spinning the Disc, riffle though the inputs and one of them should show. Could it be the disc itself? Are you loading it correctly? Some DVDs will spin but not play anything if loaded up side down.
I know that's not much help, but if the RCA jacks are connected properly, I can't think of anything else (simple) that may cause it to fail. I guess the next step is to start the trouble shooting by removing the DVD source by attaching a different DVD player so you can rule out the TV. Good luck! Come back and let us know how things work out, that's how we learn here.