I have no sound on my computer

Well what have you tried to do so far? Have you turned the volume up? Is the device working in your device manager? Have you tried reinstalling it? Are you using external speakers?
 
Is the cable frayed? Are your drivers updated? Is your system on mute? Do you have an extra audio cable plugged in, this may interfere with your main speaker output.

Try to be more concise with what you are asking next time as what you are asking for is very vague.