No sound

[-Ghost]

I've had a surround sound system hooked up to my imac for quite a while now with no problems until yesterday when I got an external hard drive for Christmas. It wasn't formatted for mac so instead of reformatting it I just downloaded some software stuff that a few blogs and threads recommended for pc/mac use: MacFuse and NTFS-3G.
I'm not sure they're the cause of the problem, but I'm pretty sure I lost sound around the time that I hooked up the hard drive.

I've tried restarting my comp, and I've checked the sound settings and it's set to Digital Out with no other options. I've also tried unplugging my hard drive, but that didn't seem to work either.

What do I do?

 

[Cave Man]

Two things to check. First, disconnect the optical cable from your receiver and make sure it has red light coming through. If so, then ensure your receiver is set to take digital input on the channel to which it's connected. My Onkyo required me to assign each optical input (2) to the appropriate AV channel (5 of these). It may be that yours somehow became disconnected.