The solution to the silent built-in speakers of the ASUS UX21E series is as follows:
1. Check the volume
Please check whether the system volume is set to mute or adjusted too low. Please press the FN+F10 shortcut key or unmute and increase the volume in the volume control panel.
2. Check whether external speakers and headphones, HDMI cables, USB audio devices and other audio devices are connected
Please try to remove these devices and then test the built-in speakers of the laptop/Easy Computer .
3. Check the sound card driver
Please click the "Start" button, enter "Device Manager" and then open the "Device Manager". Double-click "Sound, Video, and Game Controllers" and if the sound card is listed, it is installed. If your sound card is not listed, try downloading and installing the sound card driver from the ASUS Download Center.
4. Use the Microsoft Troubleshooting Program
Microsoft has designed a detailed step-by-step troubleshooting program to solve common audio problems. This troubleshooter detects the version of Windows your computer is running and then modifies troubleshooting steps accordingly.
5. If the problem still exists, please try to use the hidden partition recovery system on laptops pre-installed with Windows system.