Hi Tim Baures ,
- where your code is located? may be the flashed .bin and .hex are located in RAM!
- Please refer to this application note to verify your hardware implementation: Getting started with STM32F4xxxx MCU hardware development
Does your design pull BOOT0 Low?
Do you initialize all the clocks and pins your application needs? Debugger gets chip in a viable state for it's own needs.
Thank you both of you but I managed to solve the problem.
It was actually due to the ST-Link device that was still plug to the MCU board and keeping it from running the program (even though it wasn't plug to the computer and not powered on...)