I am trying to find out why the Handwheel on Sinumerik 810d SW2.4 "quite old" not working.

I checked the hardware connections and signals with oscilloscope they looks oK

also:

DB10.DBB68= 0000 0101

DB10.DBB100=000 0010

the manufacturer provided three buttons to select  x,y or z axes.

we tried all the possible ways from the hmi but non worked.

Attached is some MD data that could help.

Any help please?