Hi, I am building the AR4 and I finished the build and while fiddling I got a surprise mild electric shock from the PSU metal case. The power switch was turned off and I can assume it could be caused by a ground related issue. I don't study electrical engineering, so take my assumptions with a pinch of salt... So after probing some components, The metal case is only connected to earth ground. The earth ground is not connected to the DC ground. (floating) The stepper drivers ground is not connected to to the case ground. After reading some articles, DC ground is not required to be connected to earth ground usually under 48v for ground loops and interference sake. Is safe to be connected like this? I am not sure electrically what caused the shock. It was turned off at the switch. I am curious electrically why it happened. Was it caused discharging capacitor in the power supply or stepper drivers?