@OwenD
Thanks for the replying. on the Machine properties page, it shows the endstop hit "yes" for x axis without any wire connection to x-endstop. I've checked to physical short and there is none on the pin. With the x-endstop connected the value "yes" always stays the same high.. I measures the x-stop pin and it's value is 3.3V. So it look like the value is stuck high and does not get pulled down when engaged..