This is a weird one for me - when the RPi is connected USB to Arduino USB, the power supply blinks a green light. If I disconnect the USB (unplug the USB cable), the RPi boots fine and is connected to the cloud.
In the course of troubleshooting, I plugged the USB cable back into the Arduino with power on, and the cable heated up enough to melt the outer shield.
Seems like I have power coming across the USB cable. Any thoughts/ideas on how to verify the Arduino/RAMPS is ok? Or, where the current is coming from?