Drivers overheat

I purchased an Smoothieboard 5X V1.1 to replace the electronics of my CNC.
First, I updated the firmware to the latest version available for CNC (commit 7467633) and then I modified the basic configuration of the stepper motors as follows:

alpha_step_pin 2.0 # Pin for alpha stepper step signal
alpha_dir_pin 0.5 # Pin for alpha stepper direction, add ‘!’ to reverse direction
alpha_en_pin 0.4 # Pin for alpha enable pin
alpha_current 1.2 # X stepper motor current
alpha_max_rate 1400.0 # Maximum rate in mm/min

beta_step_pin 2.1 # Pin for beta stepper step signal
beta_dir_pin 0.11 # Pin for beta stepper direction, add ‘!’ to reverse direction
beta_en_pin 0.10 # Pin for beta enable
beta_current 1.0 # Y stepper motor current
beta_max_rate 30000.0 # Maxmimum rate in mm/min

gamma_step_pin 2.2 # Pin for gamma stepper step signal
gamma_dir_pin 0.20 # Pin for gamma stepper direction, add ‘!’ to reverse direction
gamma_en_pin 0.19 # Pin for gamma enable
gamma_current 1.0 # Z stepper motor current
gamma_max_rate 300.0 # Maximum rate in mm/min

As soon as I start the engine rotation, the driver becomes hot immediately and goes into protection mode.
For the installation I followed the official guide for CNC:

How could I solve?


That is extremely odd. The only thing I could think of, would be extremely out-of-specs stepper motors, what are your stepper motors, and their specs such as voltage, current, inductance etc?

I used the stepper motor Vexta PH266-E1.2 (1.2A, 5ohm, 6V).
I’m currently powered the board with a 12V power supply