Step1:Check whether connect the audio cable from PC.
Reason:VGA cable only carries video and picture information, no audio information.
Solution:Connect audio cable from PC
Step2: You need to select “PC” using the source button on you remote.
Reason:Select the correct source
Solution:Select the PC source, alternatively connect your TV using a HDMI cable if your PC has a HDMI connector, HDMI can transport digital video and digital audio together.