Mazda 626 GF blower spins

Hello together, recently the ventilation of my 626 GF spins. I have already searched the Internet and read the articles here and found nothing. I even assume that the problem is a known one, because I have found various partial approaches in posts, but nothing that fits 100%. So the problem is that the climate automation is in principle probably functional, but the direction of the air flow is not changed. So display displays e.g. windshield and/or footroom, but air always comes from the nozzles of the dashboard. Even in manual mode, the air always comes from the middle nozzles, no matter what mode I choose. Otherwise, the system reacts both in car and in manual mode to all the on/off/off/eco switchovers, i.e. ventilation strength, climate/off/eco, temperature adjustment. Does anyone have any idea what this could be? And is this the thing that you can repair yourself?