No matter use what way to change the tool of the tool changer, it is not rotating then there will be an alarm display on the CNC controller, and the air switch for the tool changer has tripped.

Check below to solve the problem:

1-      Is the mechanical part of the tool changer stuck?

2-      Any power phase lost of the tool changer?

3-      The contactor or the isolating switch of the tool changer has problem or not?

4-      Any problem of the tool changer’s motor?

In this case we found the mechanical part of the tool changer was stuck, get rid of this the machine resumed.

4 station tool changer specification:

http://www.cncmakers.com/cnc/controllers/Tool_Post_Turret/4_Station_Tool_Posts.html