The Logitech Z-10 Interactive Speaker System is a two-speaker set with a full set of controls on the speaker, including volume, treble/bass and playback controls. Getting your Z-10 speakers to work with your computer is typically a straightforward process involving installing the Logitech LCD Manager software, but if your speakers don't produce any sounds, there are possible solutions to your problem.
Confirm that the cable connecting both speakers is secured on both ends. You should also confirm that the USB cable connecting the main speaker to your computer is tightly inserted on both ends, and that the cable is in the correct slot on your computer. Test multiple USB slots on your computer in case the one you are using has gone bad. If possible, try a second USB cable to confirm the problem is not with the cable itself.
Confirm External Playback Device
No sound will come out of your Z-10 speakers if they are not selected as the default playback device for your computer. To confirm this, open the Control Panel from the Start menu. Double-click the Sounds and Audio Devices icon. Click the Audio tab. Under Sound Playback: Default Device, choose the Logitech Z-10 speaker from the drop-down menu if it is not already selected.
Restart the Computer
Unplug the speakers from your computer. Plug them back in, then restart the computer. Sometimes a restart is all that's necessary to make the speakers work again.
Check Volume Controls
Press the "increase volume" button on your speaker to confirm that the speakers themselves are not set on mute. Open the Control Panel from the Start menu and double-click Sounds and Audio Devices. Click Speaker Volume on the Volume tab. Drag both slides all the way to "high" and test your sound.
Try Additional Devices
Plug your speakers into an MP3 player or another computer to see if audio comes from the speakers. If the speakers do not work across multiple devices, they are likely defective. Contact Logitech about a replacement set of speakers if you are still under warranty.