For Houston users

I noticed Fader 8 of my Houston is faulty. Also when I do the calibration, the Houston doesn’t recognize the position of Fader 8 properly. The fader goes up faster then the rest of the Faders. “Fader 8 gain out of range” is the error message.
Is there a way to fix this? Can I open up the unit and clean the fader to fix this? I’m a electronics engineer, so this shouldn’t be a problem…