stm32h725ZGT6 custom Board Hangs

[Sakthi_Murugesan]

Hello STM32 Community,

I’m working with a custom board featuring the STM32H725ZGT6, and I’m encountering some issues I hope you can help with. Out of the 10 boards I've assembled, 7 are functioning perfectly. However, on a few boards, the MCU isn’t being detected in STM32Cube Programmer. When it does get detected, I receive the following error (screenshots attached).

To troubleshoot, I’ve attempted the following:

• Reflowed the MCU with hot air and checked/reballed the pins
• Tested the MCU on another working board (still facing the same detection issue)
• Replaced the MCU with a new one on the problematic board (issue persists)

Has anyone experienced similar issues or have suggestions on what might be causing this inconsistency? Any guidance would be greatly appreciated!

[SofLit]

Hello,

Review your schematics first, mainly VCAP capacitors:

[Andrew Neil]

Check against AN5419, Getting started with STM32H723/733, STM32H725/735 and STM32H730 Value Line hardware development:

https://www.st.com/resource/en/application_note/an5419-getting-started-with-stm32h723733-stm32h725735-and-stm32h730-value-line-hardware-development-stmicroelectronics.pdf

Also check for other app notes:

https://www.st.com/en/microcontrollers-microprocessors/stm32h725zg.html#documentation

[genesis78]

I'm having a similar problem with STM32H725RGV6s. I have found that on the boards that don't work the voltage at the VCAP pins is 0.12V, when it is supposed to be in the range of 1.1-1.3V. This is the post I've opened in case you are interested in cross-referencing problems or in case a solution appears: https://community.st.com/t5/stm32-mcus-products/issue-with-vcap-voltage/td-p/740895

[Tesla DeLorean]

Focus on the pin usage, and supplies. Orientation looks Ok.

Check NETLIST for islands which aren't connected, but should be, ie mispelled naming

Check incomplete boards for continuity on the supplies.

Check pin designations on symbol vs datasheet