My STM32F302C8T6 only runs the program when the code is loaded. If I reset it or power up, it does not run.

[JMart.13]

Maybe is a hardware problem since the microcontroller is on a custom board I designed. The problem is the following:

The microcontroller only runs the program the moment I load the code, if I reset it or power up the board after a power-off it does not run the program.

This is the following circuit for the reset and BOOT0 pins:

I program the microcontroller with an external STLINK. 

Thanks a lot for any help.

[TDK]

And does J1 have any jumper? BOOT0 must be grounded to run user code on reset. On some chips, the option bytes can override the BOOT0 pin.

[JMart.13]

Yes, BOOT0 has a jumper to ground.

[TDK]

Probably it is stuck during startup in your startup code then. Attach a debugger without resetting it to figure out where the CPU is. Could also be some other schematic error not shown in the snippet provided. LSE can take a while to come up and could be timing out. Same for HSE.

[JMart.13]

Hum ok ok, is strange because I generated the project using the STM32Cube IDE so I guess the startup code is ok, but I will have to check it.

[JMart.13]

Ok, i figured it out, there is a short in the BOOT0 pin and with a pull up resistor and is maintaining the pin HIGH. Will try to fix it and make an update later. Thanks a lot