Also check the BL3000's are set for 'audio' not 'video'. You can daisy chain the speakers. If yçu have any non-amplified speakers, try them in the DIN speaker outlets and see if you have sound.
Try the 'Mute' touchpad when you have the speakers connected in case the mute function has been activated.
OK, just now seen your picture and the 2 lines for volume mean the mute circuit is enabled. Press the mute section of the control panel and you should hear the relay click and sound appear.
Dave.