MacBook Audio Output Not Working, Except for Garageband?

Good day everyone,

I have a 13-inch MacBook '08, current version 10.6.8 (can't upgrade to OS X Mavericks – hardware is too old), and I've had a serious problem, and I feel that I've tried EVERYTHING to fix it.

My Macbook audio output does not work AT ALL while trying to stream video (i.e. YouTube, Vimeo, etc.) or listen to music. When I play with the audio adjustment buttons, it doesn't even make the "popping" sound. It DOES however have audio output when I open Garageband and play the instruemnts i.e. Grand Piano. It also plays the "start up" sound when I boot my MacBook up. Otherwise, the audio seems to not work at all.

I've played with the "Sound" settings on "System Preferences." I've played with the audio jack (note: there's not red light, so that's not the problem), I've blown into the hole, stuck paper clips in there and fiddled around... nothing. Please help, I'll take any advice!

Thanks in advance.