No device found on target (SWD connection)

[Ajaho]

Hi Community,

Prelude: I soldered my first PCB, added STM32H743ZIT6, decoupling capacitors, BOOT0 switch, NRST with resistor to ground, 5V->3.3V LDO, powered up by USB and 4-pins SWD for debug (PA13/DEBUG_JTMS-SWDIO and PA14/DEBUG_JTCK-SWCLK pins). Checked power supply with multi-meter, decoupling capacitance, no short circuits, MCU pins are soldered norm and everything seems ok. I had some problems in process and *maybe* MCU is damaged, but before replace it I would like to ask have I did all right to check MCU with ST-LINK V3 and STM32CubeIDE ?

I would like to mention, that my PC USB ports output only 2.6V, not 5V (ST-LINK runs ok, but maybe this is the reason?)

To connect ST-LINK to SWD I used Bridge connector CN9, choosing IO0 and SCL pins.

In STM32CubeIDE I tried both GDR Server and OpenOCD with the same result, except OpenOCD mentioned, that 0.0000 voltage is detected (although I checked immediately with meter and voltage exists).
I also has USART interface and USB on board, maybe there is the way to check MCU with them (with or without ST-LINK)?

Thank you for available advice!

[mƎALLEm]

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@Ajaho wrote:

I soldered my first PCB, added STM32H743ZIT6

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As it is a custom board you need to share your schematics.

Thank you.

[Andrew Neil]

First checks:

https://community.st.com/t5/stm32-mcus/how-to-solve-debugger-connection-issues/tac-p/698105/highlight/true#M956

then see the rest of that article.

Please show the schematic of your PCB, and the full log from STM32CubeIDE.

https://community.st.com/t5/community-guidelines/how-to-write-your-question-to-maximize-your-chances-to-find-a/ta-p/575228 

Can you connect successfully with CubeProgrammer?

Is it a genuine ST-Link ?

https://community.st.com/t5/stm32-mcus/how-to-recognize-a-genuine-st-link-v2-versus-a-cloned-one/tac-p/703663/highlight/true#M965 

Have you tried with NRST connected to the ST-Link, and using the 'Hardware reset' option for connecting?

 

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@Ajaho wrote:

I would like to mention, that my PC USB ports output only 2.6V, !

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Well, that's definitely faulty!

 

[Ajaho]

I will check the article.

> Can you connect successfully with CubeProgrammer?

I did not try, will try and see.

> Is it a genuine ST-Link ?

Yes.

> Have you tried with NRST connected to the ST-Link

It is not available with current design (maybe with some trick if externally connect MCU pin by wire externally.. maybe will try).

> Well, that's definitely faulty!
Yes, but it is ok for MCU run and it seems ST-link also works well.

 

[mƎALLEm]

Not sure about the decoupling capacitors value as the screnshot has bad resolution, but the recommanded decoupling capacitors value is 100nF with one 4,7uF in parallel:

From AN4938 "Getting started with STM32H74xI/G and STM32H75xI/G MCU hardware development"