LSM 900 Inverted - Z piezo and internal focus motor
The microscope is equipped with a Z piezo drive and multiple stage inserts.
To use the Z piezo, you have to be using the Pecon insert.
You'll also need to enable the Z piezo in Tools/Options/Acquisition/LSM/Enable Z Piezo
The universal (k-type) insert (the one with the adjustable slide clips) sits lower on the stage, below the Z-piezo drive (see image). The Z-piezo drive has to be disabled as above when using the universal (k-type) insert.