I recently bought a used MK3 in great condition secondhand. All the light's turn on beautifully, although the buttons on the entire bottom left square section of the MK3 do not respond. The Pads, upper knobs and buttons work great but when I attempt to click "Play", "Rec", "Shift", "Pitch", "Volume", etc. I get no response from those buttons. Could this be a problem with the hardware settings or am I dealing with a faulty MK3?