Mbox Pro 3: master volume knob won't affect volume at all

[Veledron]

Hi everyone,

Unfortunately, there is no official Avid reseller to take on repairs of music hardware in my country, so I'd like to get some clues.

The master volume knob on my Mbox Pro 3 just stopped working. It can be turned hard either to the left or to the right, but that won't affect volume at all. I can change volume using headphones knobs, Mbox control panel, or knobs on my speakers. But the sound interface's master knob is dead.

Is this a definite hardware failure? Or probably there might be something else, like disabled settings in control panel, or so? Would be grateful for any hints.