Help! Speakers and headphone jack have no sound

Hello everybody , last night I was kicking back listening to iTunes on my macbook. Suddenly the sound cut out. I thought it may have been the song messing with me , so I tried it again to no avail. I reset the computer and then started Troubleshooting.

There's no light in my head phone jack. I tried putting head phones in there and twisting them around, oh and by the way, nothing was plugged in when it happened. I've been searching for an answer but unfortunately my headphone jacks do not work either. There's also no sound during start up or any time, not through internal speakers or headphone jacks.

So, I'm lost. I have no idea. Please help I own my computer for music and if it can't play sound, it's useless to me.

First thing I would do is reset the PRAM. Shut down the computer, and immediately upon powering it on, hold Command-Option-P and R keys together until the computer reboots and chimes 2-3 times. Hopefully, after the first time, the chime will come back and sound will return to normal.

Make sure you did not accidently hit the F10 key and muted the volume.
In System Preferences under sound what does your output say and volume level?
I would do what EvenStranger suggested I overlooked the no sound at start up.

I tried all the buttons , i hit f10, i tried messing with the volume keys, i tried unplugging headphones, will resetting the PRAM make me lose any of my information? I have lots of music and I don't want to lose it.

No sir, it's non-destructive. PRAM stores little bits of information like volume level, brightness. Occasionally, it will get corrupted and need to be flushed. It has no bearing on your user data at all.

ok , i gave resetting the PRAM a shot, still nothing... nothing from the internal speakers and nothing from the head phone jack ... like i said, it stopped in the middle of a song, just cut out, and now theres no sound whatsoever, no start up, no button effect, no itunes ... just nothing. In my preferences internal speakers is selected and I have no options to change it , even if i have headphones plugged in... what are my options? is this software? should I upgrade to snow leopard? im running leopard right now .

One additional test I can think of... launch GarageBand and see if the software will reload the audio kext (kernel extension, or driver). However, the fact that resetting the PRAM didn't resolve the issue AND you're getting no startup chime, AND the audio output settings don't change would indicate to me that the audio chipset is possibly fried. At this point, my best recommendation is to take it to an Apple Store or Apple Service Provider, let a technician check it out and give you a less speculative evaluation. If the sound processing board is fried, you're looking at a mother board replacement - about $300 if you ship it in to Apple's repair facility.

Similar issue - all of a sudden, no sound. However, the restart "chime" is as loud and clear as ever.

Here's what I see on the screen:

Volume button at top of screen - click - and it looks like it is greyed out, plus volume control at max. Mouse clicks do nothing to move the volume 'circle' up or down.

Using keyboard commands (F10-12) no response with one touch or holding down key. Note: the 'mute' icon is present below the volume slider indicator, still maxed out.

Before this happened, watching vidoes and music - never had any problem at all with sound, either with built-in speakers, or the Bose speakers bought to improve sound.

More reboots - nothing.

Any suggestions? Thanks in advance.