I have a Discovery F4 Board and purchased recently a China Board from *bay (Ebay-Artikel Nr. 272501820584?) with the same uC (STM32F407VGT6). I thought a cheap way to test my code and put it into my project. I have a sample code which works on the Discovery and i flashed the code with my Nucleo Board as programmer into the China Board which was a success. I tried two ways, first the SWD Header on the Nucleo like here: (https://developer.mbed.org/questions/7974/F401RE-C...) i also soldered a cable to the RESET Pin and connected it to the Nucleo Header Pin 5. I flashed with ST Link utility, read back and compared - no differences. Second i put a jumper on BOOT1 (BOOT0 and BOOT1 have Pullups) which pulled it low and entered the Bootloader, flashed with ST Flash Loader over UART1 which also worked (read back and compared). I then put a second jumper on BOOT0 - so both BOOT Pins are LOW, and the uC SHOULD start from Flash - but nothing. I am really stumped because i searched a lot and it should work. The code is definetely working, it is in the flash memory, the uC is alive through the SWD interface (i can see the Device, DeviceID, RevisionID,.. in the ST Link Utility) the Revision corresponds with the Chip (it is 2.0). Anybody any tips???