If so, you connect them to some other source to rule out a problem with them. Some are fused and some fuses are hidden. You could also try headphones if you have a set. I'd think you've already ruled out such as the speakers being muted.
Twice yesterday our electricity went off while the computer was on. Now I get no sound from the speakers. Audio data does come in, since I see the graphics when I play internet radio, and in Audacity if I record it. Speakers are enabled. I use Windows 7.

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