Why is my sound not working?

[Retribution]

Please help! My sound started not working but if i turned up the volume with the keys it made the "blip" sound. I restarted my computer and now it doesn't work at all! What do I do?

I am using Mac OS 10.4 and MacBook.

 

[eman]

Do you see a red light shining out of the external head phone jack, while the macbook is on?

Also, try restarting your macbook and holding down the "option + command + p + r" keys at the same time, until you hear three chimes, then release keys.

 

[G5power]

If you are using external speakers plug them into an iPod or something and you can verify that the speakers are ok.

Also if you look in System Preferences under Sound, verify that the mute box is not selected.

 

[Retribution]

No red light and when I press command + opt + p + r it just does the "dun" sound?!?!?!?

And sound is not muted on System Prefs.

 

[eman]

No red light and when I press command + opt + p + r it just does the "dun" sound?!?!?!?

Did you hold the keys down until it completes three "dun sounds"?