I have a Tevo Tornado, it seemingly connects fine, it is recognised by the software and it turns on. Any command I send over USB is not executed, as if it's not registering them. I tried on Cura and Pronterface and the printer is unresponsive. In particular in Pronterface it displays:
but nothing is executed.
This is part of a broader set of problems I am trying to diagnose on the printer; most of them are explained in this question. I am trying to section off the individual problems and fix, bit by bit, the whole printer.