My volume knob has become loose/unresponsive - what should I do?

You may have a loose volume pot.  This can happen when the nut that holds the volume pot in place becomes loose.  This can be easily accessed and tightened without opening the speakers up.  Try this:

1) Pull the plastic volume knob off the volume pot.  Depending on how tight it's on, you might be able to pull it off with just your fingers. If not, you may need to cover the knob with a soft cloth and pull out with pliers.

2) Use a deep well 10mm socket (or socket driver) to tighten the nut around the volume pots shaft.

3) Press the plastic volume knob back over the volume pot's shaft, and retest.