The system works only with the ST link adapter connected

[AE104]

Hello,

I use an STM32F767 microprocessor on a custom PCB and test it with power off and on conditions. After uploading the codes, I powered off and on the system. Then, the system works only while the ST link adapter is connected. Do you have any suggestions without using the ST link adapter?

Thank you,

[TDK]

Start it without the debugger attached, then attach the debugger and connect with resetting and find out where the code is. Verify NRST is high and the chip has power. We don't know what "works" means.

If it has power, it's running code somewhere. Either instrument the code or use the debugger to find out where it's stopping.

[AE104]

@TDK​ 

Thank you for your comments! First of all, I want to share the NRST connection on my design. Based on the current connections, I uploaded the code by pressing the 'Run' button on the CubeIDE. After uploading the codes, I removed the ST link adapter and powered off the system. I removed the 0 ohm resistor, then I connected the NRST pin of the processor to the 3.3V. After that I powered on the system, and the system worked. Looks like that the problem was solved! Do you think is there any strange things that I did? An everything should be like that what I did so far?

[TDK]

NRST should never be tied to 3V3. Doing so prevents the chip from pulling it low for internal resets. It has an internal pull-up so doing so in unnecessary anyway.
Having the debugger attached but not powered will pull NRST low. Could be what is happening.

[AE104]

@TDK​ So what should be the ideal connection for the NRST? Such as connecting it to the GND through a 0.1 uF capacitor?

[AE104]

It was solved by connecting 0.1 uF connected to the NRST pin. Thank you! @TDK​ 

[Tesla DeLorean]

BOOT0 pulled to ground?

[AE104]

Yes, through a 10kOhm resistor.