I can’t fix the crap above – working with STM32CubeIDE you get used to SW bugs and slow perfomance as can be expected by most Java applications – that screen is something you see a lot…
I got the MCU running with no crystal, added a 25Mhz crystal and it worked. Added some other components and detected that my crystal was very unstable on/off.
HSI worked fine, but crystal was moody.
Double checked all MCU pins, replaced crystal, measured noise on DC/DC before I finally replaced the 18pF capacitors associated with the crystal and voila.
1/2 day wasted on a bad soldering point…
These bugs are a bit hard as you bring a new board to life and don’t have the confidence that this should work. I have used this crystam before, but I had a new DC/DC next to it + it is always the possibility of a dodgy MCU…