Trouble with Z axis

Hello, I have two M300. I have printed the same part on each machine. The part has a thickness of 3mm.
On the first one, the part is correct, 3 mm. On the second machine, the part is not correct. Its thickness is 4.8mm (same G code)

I suppose it is a problem with the z stepper motor. Or with the driving card of the z motor.

Have you already had such a trouble ?
What is your analysis?

Thanks.

Regards.

Hello Vincent,

do you have any picture that shows the difference between these two models? Could you also provide a .zcode file? Since when it comes to thickness - are you sure you are referring to the Z axis (height), not X/Y one (depending on how the model is placed)?

Did the problem occur out of sudden, or have you recently noticed any deterioration of quality?

Also, when it comes to the Z axis - please check if the platforms moves all the way up and down (maintenance → move platform)?

Best regards,
Karolina