To enable the sound suddenly disappeared, you can use the volume control of the speakers. Almost every laptop has a volume control, which is located on the side panel of your machine. If the regulator was fixed to the value "0" or "1", the scrolling controller will provide an increase in system volume. Usually this is the main reason of loss of sound on laptop.
The second way to turn the sound on the laptop is changing the settings of the mixer. In the lower right corner of the screen, near the clock is a speaker icon. When you double-click this icon, you will see a mixer of your sound card. The main volume of the system can be set to "0" or completely turned off. Adding this setting will give the appearance of sound in the laptop.
Another way to test the sound on your laptop is the volume control using hot keys of your car. Each laptop has its own keyboard shortcuts, which are responsible for the proper operation of certain components, including sound work. To turn off mute, press the Fn + the speaker icon. Most likely, the keyboard will appear 2 icon speaker: pressing one button will add the sound and press another to turn down.
If the above-described methods are not suitable, check the speaker connections to the audio input socket of the laptop and the network. Also check the connecting cables between the columns. After connecting all the wires that have been disconnected, you will hear sound in the speakers.