Sony VAIO computer - Manual (Page 155)

Speakers
Why won't my speakers work?
 Make sure the speakers are properly connected and the volume is turned up loud enough to hear sound.
 Your speakers may not be designed for computer use.
 If the speakers have a mute button, set the button to off.
 If the speakers have a volume control, make sure the volume is turned up loud enough to hear sound.
 If you have connected an audio cable to the Headphones jack, disconnect the cable and use the speaker cable that
was supplied with the speakers.
 If you are using battery power, make sure the battery(s) is inserted properly and is charged.
 If the speakers require external power, make sure the speakers are connected to a power source. See the guide
that accompanied the speakers for more information.
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