Check both the volume controls are turned up on the amps and that they are all on (located at the bottom of the rack). Also check ‘Mute’ isn’t enable on the computer itself (open ‘Control Panel’ and view sound options).
If this doesn’t work, the speaker itself may be faulty. Contact us on 0844 414 2595.
Alternatively please submit a support request by clicking the 'Submit Request' link at the top of this page.