STM32H747-DISCO Board - ST-Link V3 - Target Not Found

[MichaelZemah]

I'm working on the STM32H747-DISCO Board, and studently the onboard ST-Link-V3 stopped recognizing the STM32H747 MCU.

No matter what i do, it wont find the target,

1. when I connect a simple STM32F411-DISCO everything works as expected.
2. Rebooting the Power won't help.
3. Updating the ST-Link FW won't Help.
4. no matter what debug configuration I do it won't recognize the target MCU.

Not only that the CubeIDE and CubeMX are very buggy, now the MCU is dead ???
this MCU costs a lot and it's dead ?

very disappointing !!!!
I request that ST representative will help me sort this matter.

[jiangfan]

There is one case the MCU (such as STM32H7) seems dead: it is due to mismatch firmware vs. hardware configuration, for example, hardware configuration is SMPS power (or LDO power) for MCU, but firmware enables only LDO power (or SMPS power) for MCU. For such case, recovery is possible, by changing the boot setting of STM32H7 to boot-from-sram, and connect to PC software such as CubeProgrammer, then erase full chip.

[jiangfan]

by default, after RESET, both SMPS power and LDO power are enabled for STM32H747.

[MichaelZemah]

Do I need to change a boot resistor of the MCU ? Or change the value given to Boot0 or Boot1 pins ? 

What should I do exactly ? 

Ive tried connecting to the MCU wice CubeProgrammer before and erase, but couldn't.. 

What am I missing ?

[jiangfan · Accepted solution]

You may refer to: UM2411 Discovery kit with STM32H747XI MCU, in case of "A deadlock occurs if the board SMPS/LDO firmware PWR configuration does not match the hardware configuration".

chapter 5.2.3 SMPS/LDO power supply of the document:

Caution: A deadlock occurs if the board SMPS/LDO firmware PWR configuration does not match the
hardware configuration: after the reset, the ST-LINK cannot connect the target anymore.

1. Power off the board.
2. Connect pin BOOT0 to VDD using a wire (or short R192).
This changes the BOOT0 pin to 1 instead of 0, thus changing the device boot address to boot address 1 and making the bootloader start in System memory. This avoids starting firmware in the user flash memory with a wrong SMPS/LDO configuration versus the hardware board configuration.
...

[Tesla DeLorean]

This is a topic that's been covered here a few times.

https://community.st.com/t5/stm32cubeprogrammer-mcus/error-to-connect-to-target-stm32h747i-disco/m-p/294136

https://community.st.com/t5/stm32cubeprogrammer-mcus/stm32h747-discovery-kit-not-debug-programmer/td-p/237335

https://community.st.com/t5/stm32-mcus-products/get-stm32h735g-dk-out-of-deadlock/m-p/157094

[MichaelZemah]

Thank you, the MCU is now operational !!