Data not transmitted when powering Nano 33 Iot from a MKR Board (GSM 1400)

Official Hardware Nano Family Nano 33 IoT
1

Hi all,
i’ve connected a MKR GSM 1400 board to Arduino Nano 33 not through the pins 13 (Rx) and 0 (Tx).
All the systems works as expected when powered each one by usb ports or by a micro usb power supply.
Connecting VCC and Ground from MKR Board to the respective Arduino Nano, the power led of the nano lights up correctly but data are not transmitted to the MKR Board anymore.

Any suggestion ?

Thanks

2

Connecting VCC and Ground from MKR Board to the respective Arduino Nano, the power led of the nano lights up correctly but data are not transmitted to the MKR Board anymore.

Please post a schematic (pencil and paper photographed is OK) of your system

3

I've attached the schematic.

Thanks

circuitoarduino.png
circuitoarduino.png1492×1514 344 KB