MK2/9 defective Axis repair need help on schematics

Hi,

can anyone help and answer me the question below ?

there are 10 x 74HC14 (U1-U10) on board and i have x axis and some output channels defective due operator fault :bat: ...
i need to know which chip is responsible for what output.

thanks

Thomas

U3 E U4 step U4 PIN 6 dir PIN 8 U3