Thank you for the circuit diagram you posted. This was greatly helpful to fix my unit. You see, in case of a short at output sometimes fuse won't help. And 2 power thyristors inside block for CNC3020 don't have marking (its erased by chinese).
I e-mailed chinese manufacturer and they told me that MFG# of thyristors are S2516BH, as well as I got info about spindle motor, its max 95V DC and max speed 8000rpm.
So, you can now easily fix the ECU module if needed. Thanks