Welcome to the forum.
We don't know anything about your computer model or Operating System.
I can offer the following:
- Most "no sound" issues can be fixed by going through the configuration and rechecking and / or resetting the parameters.
- Tak a look at the following document for your OS to find out what what may be happening and to see suggestions on how to fix the issue.
No Sound from the Speakers (Notebooks Windows 7)
Notebooks - No Sound from Speakers (Windows 8)