No sound! Laptop!

I have a Dell laptop, 500mHz PentIII proc, Windows XP Home, 256MB RAM. The laptop works great except for the speakers. The sound comes and goes, mostly goes. There is probably a 1 in 20 chance that I will have sound when I boot. Device manager looks fine, no errors or extra beeps on boot. I've tried pressing the speaker shortcut buttons, with the fn button, and I don't get any change (when speakers are on they don't shut off, and vice versa).

Any help is appreciated.

 

Sounds like something has gone awry inside. I'd be inclined to get it in for a repair (or back to the manufacturer if it's still under warranty).