7I76e volt readings

Hello
try to configure a 5 axis machine
the machine X Y Z A B is working in all directions exept B-
When i mesure the volt in the  TB2 0-3 step and dir i have values from 0 to 5 volts
When i mesure the fault axis TB3 4 step and dir i have values from 1.45 to 5 volts(not 0 as the 4 previus axis)
Is this normal?
What coold cause  that?

Sounds like the driver chip for STEP4/DIR 4 has been damaged
(U24 74ACT04)

Probably from accidental connection to a voltage outside of the 0 to +5V range