tbh I do not think that board is broken as i never have heard of one that broke.
Might be best to upgrade the firmware on the device and "start fresh" with new settings for the cnc. Just follow the manual.

I'm not sure if your machine has this:
http://www.bzt-cnc.de/en/shop/electr...e-mit-watchdog

But that could also be whats causing you trouble. It might be the watchdog or whatever tripping from "noise".