Stepcraft D420 X Axis Blocked

Hi
I have a stepcraft D420 that I bought some months ago but never got a chance to play with it so far.
Finally got some time to invest and go stuck for my first trial
I have initialized the table, performed the Z alignment (using the tool) and run the job (without bit just to see how it operates.
The move was only going in the Y and Z direction (but following a rectangle in the Win PC)
I stopped the job and wanted to bring the machine at the home position ... to realize that the X axis was completely blocked
I am even not abler to move it manually. I don't see any obstruction or damage.

So, what the best process to follow in this case. ?
Anything I can check. ?

thanks in advance