PinePhone Hardware Issues
The sim reader may fail to read a sim card (reporting 'sim-missing' in mmcli), possibly due to deformed pins (if you put your sim adapter in without a sim), or due to a warped sim card adapter.
A possible solution is to bend the pins back (using a plastic spudger), and/or use a different sim card adapter (which your carrier may provide to you).
USB-C Side Board
All USB-C Side Board issues can be fixed by replacing the USB-C Side Board
The microphone may stop working or occasionally stop working or give off static when power is plugged in.
The bottom speaker may stop working, especially if you have recently mishandled the USB-C Side Board, stressing the point of connection between the circuit board and the circuit flex. This can be fixed by touching up the solder between the two.
Place new issues here.