Reasons why computer speakers stop working include faulty audio cables, corrupted or missing audio drivers, and modified or muted volume on the software level. Other reasons include a disabled sound card in the Device Manager and other playback devices set as the default audio option instead of the speakers.
To check whether the speakers or audio cables are faulty, connect them to another computer or audio device, and test them. If the speakers don’t work, replace the audio cables, or reconnect and solder the damaged parts. To check whether the audio drivers are missing or if the sound card is disabled, open the Device Manager dialog box by accessing the Control Panel, clicking on the Hardware and Sound link, and selecting the Device Manager option. Double-click on the Sound, Video and Game Controllers option, right-click on your sound card, and select Properties. Check the Device Status box to ascertain the problem, and select the Update Driver option in the Driver tab to fix a driver-related issue, or click on the Enable button to enable a disabled sound card.
Make sure to enable the sound on your computer by clicking on the speaker icon in the taskbar and selecting any volume value other than zero. To set your speakers as the default audio option, right-click on the speaker icon, click on Playback Devices, select your speakers from the list, click on Set Default, and then click OK.