I have disabled the ability for the USB port to provide power on an R3 Uno by removing the small mosfet next to the USB port. I don't see the same thing on the R4 so am wondering if I can do this or not? The board will be connected to a PC via USB 24x7 but powered through the 5v pin from an external 5v power supply. When that power supply turns off, I want the board to turn off, even though it will still be getting power from the PC through USB port.
The schematics don't show that level of detail anymore. Since it is a type-C USB you have 4 USB power connections to cut. I would search for a non-powered USB-C cable or make your own.
Here is the relevant part of the schematic
I power my Arduino's through a USB hub with switched ports. I can switch them off and use external power but still communicate over the still active USB data and GND wires.
