I have a simple issue : I have a combinaison of RAK 4631 + RAK 5005-0 + RAK 1920 (no part have been modified at all, all is brand new) and I still don’t know why, but the 3V3_S and VDD seems linked.
As I was trying to connect a QWIIC sensor, I saw that it was powered even when IO2 is low, I disconnected it and with my ohmmeter I tested every link. I found that VDD and 3V3_S are linked when RAK 1920 is plugged.
I checked the schematics and there is a bug on the RAK1920. 3V3 and 3V3_S are connected to each other, which should not be. Unfortunately it cannot be changed (no 0 Ohm resistors there).
I reported to R&D, but on the current PCB’s it is like this.