EMI, Flickering, Black or Blank screen:
If you have verified you have the cables connected correctly (screen MUST be connected to wall power) and the screen is blinking on and off during a cut, you may be experiencing EMI. Ensure you have the controller and screen on one outlet, and the vacuum and spindle/router on a separate circuit/outlet.
Remove any power strip, surge protector or battery backup, If that does not correct the issue, consider placing ferrite cores on each cable that connects to the screen: https://amzn.to/2XDpH0O
What is emi? Electromagnetic interference - Wikipedia
Symptoms of not connecting correctly, touch doesn’t work and screen flickers black.