Hey,   today I accidentally destroyed two MCP3208 while working on my midi-keyboard. At first I thought some electrostatic voltage was the reason for this, but then I investigated further and realized that I had a strange +28V voltage measured between GND and the metal case of my controller.   Ok, here is the setting:     - I have a keyboard controller case with a metal top. It is powered by an internal PSU which gives me a clean +5V for the LPC17. On the mains connector the two AC lines