Wojtek sounds polish to me. If you are in Poland call Mark Rose at the UK office.
Mark is an old Euphonix guy and has been around at least since we bought our S5MC system eight years or so ago. He did the on site commissioning with me.
But do realize that it’s a discontinued product that was EOLed a while ago. And Mark’s day to day duties are with the S6 these days. But he has always been helpful to me.
Yes the faders can mostly be fixed by a good clean unless they are mechanically broken (knock on wood as that haven’t happened to any of ours yet).