One of my MacBooks only has sound when connected to headphones or external speakers. The internal speakers won't work at all. When no external sound device is plugged in, trying to change the volume reveals the all to familiar permanently muted graphic. The red optical audio light is stuck on inside the line out jack. This leads me to believe some sort of switch is stuck or something.. I've spoken with a tech about getting a repair, but it has to be done through my organization. According to him, it could be months before someone could even look at it. Is there anything I can do?