I have a problem with my looper.
As you can see on the photo above, the two-leveled knob has broken off my Boss RC-2. Being a boss pedal, however, it has worked just like new despite the injuries. Until today!
The guide knob can easily be turned and sure enough: it turns the drum sounds up/down.
The volume knob turns just as well as the guide, but nothing happens to the volume whether I turn it counter-clockwise or clockwise several times.
Is there a way to fix this? Any idea what the problem is? Any possible solutions?

As you can see on the photo above, the two-leveled knob has broken off my Boss RC-2. Being a boss pedal, however, it has worked just like new despite the injuries. Until today!
The guide knob can easily be turned and sure enough: it turns the drum sounds up/down.
The volume knob turns just as well as the guide, but nothing happens to the volume whether I turn it counter-clockwise or clockwise several times.
Is there a way to fix this? Any idea what the problem is? Any possible solutions?