Arm Mbed OS support forum

F303K8 "The interface firmware FAILED to reset/halt the target MCU"

Hello to all,
I have a F303K8 card that does not work anymore.
When I plug it into the USB, it is detected but a Fail.txt file appears saying “The interface firmware FAILED to reset/halt the target MCU”.
I tried to reload the firmware by following the procedure given here
The procedure goes smoothly but in the end it doesn’t change the state of my card. Is there a solution to this problem? Or is the card out of order?
Thank you for your answer
Best regards

Hello Dominique,

This might help (but no guarantees):

  • Push and keep down the RESET button on the board.
  • Connect the board over the USB cable to the PC (while keeping the RESET button down).
  • Once the board is powered release the RESET button.
  • Update the firmware (optional).

How to upgrade STLink FW: mbed-os/targets/TARGET_STM at master · ARMmbed/mbed-os · GitHub

You can also try a full chip flash memory erase with Cube Proframer tool :mbed-os/targets/TARGET_STM at master · ARMmbed/mbed-os · GitHub

Thank you for your answers.
I have tried your suggestions, unfortunately without result. I tried to use STM32CubeIDE which does not solve the problem either:

Target no device found
 Error in initializing ST-LINK device.
Reason: No device found on target.

Of course, the same program with a functional F303K8 card does not cause any problem.
So I think my F303K8 card is out of order.
Thanks for your help

Don’t give up so easily! Try to connect to the board with the STM32CubeProgrammer in Hot plug or Under reset mode. You can try also to keep the RESET button on the board down when trying to connect to the board with the STM32CubeProgrammer.

Hi Zoltan,
I have solved my problem. In fact on a card, a little joker had desoldered JP1 the target microcontroller (F303k8) was not powered. Now this board works perfectly. On a second board, the U1 circuit (ST890CDR P-channel MOSFET) is out of order (5 V in input and 0.3V in output) I do not know the cause, certainly a bad manipulation by a student.
Thanks again for your help