STM32f407vgt6 stlink v2 not connecting on PCB
Hello! I've designed a PCB using STM32F407vgt6 but I cannot get it to connect using ST-LINK/V2 via the SWD interface. When I try to connect using STM32 ST-LINK Utility, I get the following error:
Can not connect to target!
"Connect Under Reset" mode from Target->Settings menu and try again.
If you're trying to connect to a low frequency application , please select a lower SWD Frequency mode from Target->Settings menu.
No target connected
Neither suggestion in the error message solves the issue.
I have confirmed the ST-LINK/V2 adapter works because it connects to STM32F407-DISC1, which also uses STM32F407vgt6, using STM32 ST-LINK Utility and ST-LINK/V2 via SWD with no issue.
I've confirmed that the SWDIO pins, power, NRST and BOOT0 and BOOT1 are connected correctly per the wiring diagram using a multimeter and inspected all other solder joints and they all look okay. I also tried adding in 10K pullups to 3.3V on SWDIO and SWCKL but it didn't help so they are removed in the picture.
As far as "signs of life" tests USART2 is exposed instead of USART1. If at all possible I'd like to figure out what's wrong before ordering new boards.
Also the board uses crystal ECS-80-10-33-CGN-TR3 (CRYSTAL 8.0000MHZ 10PF SMD).


