The past days I've been debugging my first try at a minimal carrier PCB. I milled a PCB that has power in, CPU debug serial, USB-A and HDMI.
Though the only thing I wanted to get going so far is powering the SoM and getting a connection to the CPU debug serial.
At the moment I'm struggeling to even get the SoMs PMIC to power up. I connected everything correctly according to the datasheet. All thats apparently needed is 4.2-5.2v on the VSYS pins and all GND pins connected. I continuintity up to the mating pin of the connector and they are all properly connected, so its quite puzzling why the PMIC wont even start up and produce the 3.3 and 1.8 voltages. I do get a minimal power draw of around 10mA when attaching 5V but other than that it just seems dead.
SoM is still working fine in the dev kit carrier board so I haven't fried it either.
If anyone is interested here is the datasheet for the SoM: https://s3.us-east-2.amazonaws.com/technexion/documentation/pico-imx8m-rev099.pdf
A pic of the milled carrier board (yes the connectors are shit to solder, they have no alignment pins)
Here the excerpt from the datasheet