STLink v3 Mods not flashing STM32H7 MCU

[Ltech.1]

We have a STLink v3 Mods which is not capable of programming any STM32H7 MCU. The programmer works fine with G4s, F3s, F4s and L4s. Using the STM32Cube Programmer and 4kHz as a connection speed works fine for reading and writing. Higher speeds do not work at all.

The minimum connection speed which can be configured inside the STM32CubeIDE does not work either.

Does anyone of you experience the same?

Best Regards

[Tesla DeLorean]

Giving some kind of error? Any kind of logging of the issue?

How exactly is this all wired? Effective grounding? NRST?

[Ltech.1]

The STLink v3 Mods is mounted on a pcb which has a connector for a TAG-Connect programming cable we use on all of our devices.

The grounds are connected as well as the NRST connection. The programmer works fine on every other board we have tested as written above. The STM32H7 board works flawlessly using a STLink v3 as a programmer. Therefore I do not think that this is a hardware issue.

We use software rest mode for all our boards

STM32Cube Programmer shows these erros when trying to connect with any frequency higher than 5 kHz:

Usually:

Error: No STM32 target found!

Sometimes also this one:

Error: ST-LINK error (DEV_TARGET_CMD_ERR)

Using 5 kHz works fine.

When using the STM32Cube IDE the error is:

Target unknown error 32
 
Error in initializing ST-LINK device.
Reason: Unknown. Please check power and cabling to target.

When using a STLink v3 everything works fine as expected and we can use any frequency we want.