Please check that the AV cable is plugged into the right port. AV OUT cable Video = Yellow Left Audio = White Right Audio = Red If your TV is MONO, you only need yellow and white ports. COWON D2 only supports the official AV cable which comes with your device. And if there's too low sound, your movie file might have been recorded with sound in low volume. In this case, please try to test the movie file in the installation CD. Thank you.