More tomorrow! Kinda late here.
Ensure the stm32 is working... Sometimes weird things happen, make a full erase, try again with 0.3...
Check voltage at both sides of R4, on any doubts replace with a solder jumper.
Also, you can connect A/K directly to power, there's already a resistor for the led, R7 in the corner.
It seems J1 joins K to gnd (One wire less to worry about).
Resolder C1-C9 to remove any posibility of a dry joint.
Finally, be extremely careful with the bottom corners, the glass there is very thin, will break with just a mean look!