Hi, Hongjun,

I assume you are using contact mode. You can do a
false engagement to see if you Z-board is functional:
set the setpoint lower than A-B value, and then do the
engaging. The system will immediately get engaged. You
go to force-curve mode and let the z scanning under
full range. Then use the knobs to low down the tip
until you see the typical force curve. If you can't
get any reasonable force curve, then either the
z-board or piezo is malfunction. You can go further to
figure out the real problem in this case by measure
the piezo voltage in the cable. If the output is about
+/- 200v (I am not quite sure what the maximum) then
most probably the piezo is damaged. Otherwise you
should do trouble shooting with the z-board again. If
every thing is fine, I mean you can get a good force
curve, you need to check the engaging motor part.
Please contact me in person ([email protected]) if you
still have any problem.

Thanks,
Jianzhong