: Error: No STM32 target found!

[samuelbs]

I designed my board using the STM32L476RGT6. However, when using the ST-Link via SWD, I get the following message:

Error: No STM32 target found! If your product embeds Debug Authentication, please perform a discovery using Debug Authentication.

I have checked all connections and voltages, and everything is correct, with the proper 3.3V values.

I am sending the schematic and a photo of the programmer.

Note: I did not solder the VCAP capacitors, and there is no voltage on these pins.

 

 

 

[tjaekel]

Do you use an ST-LINK debugger?

Have you wired NRST also to debugger header?
The "UR connection mode" seems to mean: debugger wants to connected Under Reset (it wants to force a reset and connect). But if you do not populate NRST to debugger - maybe the reason.

A forum link with similar symptom:
https://community.st.com/t5/stm32cubeprogrammer-mcus/stlink-v2-not-recognizing-stm32cubeprogrammer-ur-connection-mode/td-p/581187

 

[AScha.3]

At first solder the vcap caps. And verify the voltage there, about 1.3 V . This is the CPU core supply - so the most important voltage to check.

[samuelbs]

I measured 0V on the VCAP pins and a current consumption of 60mA (STM32L476RGT6 + LC76G), which I consider very high.

I am using the ST-Link from my Nucleo board, and when I reinsert the jumper, the STM32L4 on the Nucleo board works perfectly.

Additionally, I have already checked for possible shorts in the soldering or PCB and found none.

Could this be an issue with the MCU?

[AScha.3]

>0V on the VCAP pins

= core has no supply.

So check for any short on VCAP .

 

>Could this be an issue with the MCU?

If you didnt give 3v3 to vcap or something like that (static discharge) - cpu should be ok.

If you have another board, try it; to compare.