Sony VGN-S380 VAIO User Manual page 199

Why don't the Fn+F2, Fn+F3, or Fn+F4 key combinations work?
The Fn+F2 keys toggle the built-in speakers on and off. The Fn+F3 keys decrease the built-in speaker volume and the
Fn+F4 keys increase the built-in speaker volume. The computer may not recognize the Fn+F2, Fn+F3, and Fn+F4 keys if the
correct speakers are not selected. Follow these steps:
1. Right-click the Volume icon
2. On the Volume tab, click Advanced in the Speaker settings box. The Advanced Audio Properties window
appears.
3. On the Speakers tab, select the correct speaker setup from the Speaker setup drop-down menu.
on the taskbar, and select Adjust Audio Properties.
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