Alright, before I spend ~80 euro on a logic analyzer I first want to properly measure the sides of the PCB's that are hard to reach when they are attached. I am looking for m/f jumper cables that could extend the connectors so I can lay the boards flat on the table. It somehow is hard to find these cables for 0.4mm pins, most cables are too thick like e.g. cables for the Raspberry Pi GPIO pins which are 0.6mm.
J3 (female connector on one of the PCB's) is about 13mm wide for 10 pins, so the raster size should be 1.3mm (or 1.27mm?). What would be a regular size?
And how would such a cable be called? It does not seem to be a breadboard jumper cable.
Could it be that the board that contains the Winbond and Qualcomm chips was powered separately at the factory when the firmware was uploaded? In that case I could be unlikely that I will find pins with the right votages.