ST-LINK error (DEV_USB_COMM_ERR) after changed back from J-Link to St-link

Question

I was trying to convert St-link to J-link, but after the change I want to check if return to St-link working fine. Unfortunately it doesn't work now.

When I am trying to connect with the STM32F769I-Disco I have a message ST-LINK error (DEV_USB_COMM_ERR).

Does anybody knows how I can restore the STM32 to the default state? Maybe there is possiblity to use other connection than ST-link?

I make exactly the steps from this link: https://www.segger.com/products/debug-probes/j-link/models/other-j-links/st-link-on-board/

I was trying to connect right after hard reset in the STMCubeProgrammer, but the same issue occurs. The application can see the ST-Link but it can't connect to the target.

Answer 1

I have the same issue reflashing after jlink, the above and updating my windows driver together solved the problem.

Answer 2

My OS is Ubuntu 20.04. I found, that the libusb-1.0-0 path was wrong. Stm32cubeprogrammer was loading an incorrect version of libusb-1.0-0 I found two versions of libusb-1.0-0 The right one was /lib/x86_64-linux-gnu/libusb-1.0.so.0.

Answer 3

I managed to solve the issue.

It takes me a lot of time to find the solution, but at least the board works correctly again.

For 1-2 seconds after the board was connected to PC the option "Upgrade Firmware" was not greyed out. So in case your firmware will be broken, just try to click this option. It restores the default firmware and the ST-Link works correctly.