Sorry to hear about the sound problems on your laptop. The most common cause for macbooks to act in this manner is when they think something is plugged into the headphone jack. My first step recommendation is to find a set of headphones and put them into the headphone jack. Does this clear the locks? Are you able to hear sound and do anything with headphones in? If so then remove them and see if the issue resolves itself.
If you can get good tech support for your problem, which is not an easy one, for $5 some place else that's great. $5 is the deposit it clearly should state the price... you may have missed it. Do you still wish help here? Satisfaction is guaranteed.