No Audio Playback On Logic Platinum 6.3.1, New to program on a G5 Options

[Tao Jones]

Hey, I kinda jumped head first into computer audio production and bought Logic Platinum 6 when I got my new dual 2.o GHz G5. So, I've installed all the drivers, updated to the latest version of Logic through emagic's webpage and have the latest version of OSX 10.2.8

I'm trying to learn the program from the tutorials on the Demo Songs disc, but there is no sound when I push play. The score will play visually, but I can't hear anything. I'm guessing the program isn't set up with my soundcard, but I'm not sure. What are the possible problems and how can I remedy them? Any other advice you might have for a first time user is appreciated, as well.

Thanks in advance