Hi. I'm using an OrangePi RK3399 and if the power supply from the 12V barrel jack is removed, the LTE module connected to the mPCIE port dies. Does anybody know how to make the mPCIE port work while on battery?
The mPCIE dying is due to the port being powered from the main power supply line VBUS from the barrel jack (before the BQ25700a battery charger IC, according to the board's schematics). I don't know why power is not supplied from VSYS like everything else on the board. So, what I've found is that if I want to power the mPCIE port from the battery, the reverse OTG mode from the BQ25700a battery charger IC would need to be set (allowing voltage to flow from the battery to VBUS). The problem is that even if the correct register on the BQ25700a is set, there is a resistor from the OTG Enable pin connected to GND, overriding any software configuration.

Am I missing something or is there no way to mantain the LTE module on the mPCIE port working while powered from batteries?

@edfarreraDid you ever manage to get it to work?
What kind of data throughoutput rate did you manage to get with the LTE while not on battery?
Thanks.