I have a ripspeed dv720 and it produces no sound but everything else works fine does anybody know why

Hi bud look for your remote lead or power antenna lead and connect the p-control lead from the head unit.thats what i did away it went awsome sound.

There should be a brown wire at the back of the head unit labelled 'Mute', its there so that if you have a bluetooth enabled car, it will mute the music while a call is taken. all it needs to be activated is to be earthed on say, the metal casing of the stereo, so to prevent it, cover it with tape or shrink wrap to stop it earthing