2007 iMac Snow Leopard Any idea why my external speakers would stop working? This happened after I unplugged speakers from output and plugged in headphones. After done, when I plugged speakers back in it stopped working. Headphones no longer work either. Internal speakers still do, though. I went into preferences and sounds. The external speakers are no longer showing up. Built in output is the only option available. I unplugged everything and turned everything off. Plugged them back in and turned the mac back on. Nothing. Any ideas?