Please check monitor, PC/laptop and connection.
1. Check and make sure the monitor is not muted or volume down.
2. Check the PC/laptop setting:
a. Make sure the PC/laptop is not muted or volume down.
b. Check the setting of sound output device in Windows/Mac OS has been set to monitor.
3. Check the cable connection:
a. If connected by HDMI cable, please make sure the connection is
secured, re-plug or try another HDMI (Premium) certificated
cable in direct connection.
b. If connected by VGA cable, please make sure the audio cable is connected to the AUDIO/LINE/HEADPHONE OUT port and plugged into the AUDIO/LINE IN of the monitor.
4. Try another PC/laptop or speaker for cross check.
If above steps don’t help, please contact ViewSonic service center.