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Unplug the audio cable from the laptop speaker jack to see if you can hear
if the laptop is producing any sound. If you do not hear any sound, the
problem is the laptop. If you hear sound, the problem is in the AV system.
Check the Sound Control Panel on the laptop; unmute or raise the volume
level.
Test the sound by using another file you know has sound.
Increase the Volume control setting on the touch panel or switcher.
Reselect the laptop or portable computer
on the touch panel or switcher.
