MKS SBase1.3 Endstops/Homing issues

Hi guys,
currently I'm getting my old MeCreator2 to life again. For the electronics, I used an MKS SBase 1.3 I had lying around. Re-wiring is finished, and now I'm trying to get smoothieware running, but no success. I managed to get the motors moving correctly (using the Smoothieware werbserver). But I'm not lucky with homing, so I reduced my efforts to the x-axis first. I'm afraid the endstops are not working (the LED lights up when the endstop is triggered, so its power supply is ok). I tried both X+ and X-, but even if I trigger the endstop manually I can move the axis manually in both (!) directions. And when I click the "home" button, the axis moves (if at all) only a short distance.

I attach my config file below. Thanks in advance for any helpful advice!
Hermann