NUCLEO-WB05KZ target stops responding after flashing firmware (ST-LINK errors)

[Araleb]

Hello, @STTwo-32 

I am working with the NUCLEO-WB05KZ (MB1801 + MB2032B target). I received two boards from the ST eStore.

• One board works fine: STM32CubeProgrammer detects the target, and I can erase/flash/debug with no issue.

• The second board initially connected once, but after flashing a BLE firmware example via STM32CubeIDE, the target MCU no longer responds.

Symptoms:

• ST-LINK is enumerated correctly in Windows (Virtual COM Port visible, target voltage ≈ 3.28 V).

• In STM32CubeProgrammer:

  • “No STM32 target found” or

  • “ST-LINK error (DEV_TARGET_CMD_ERR)”

• Cannot connect even when selecting SWD + Hardware reset, lowering SWD frequency, or holding RESET while connecting.

• Tried with BOOT0 jumper set to “Bootloader” and with “User Flash,” no success.

• ST-LINK firmware is up to date.

• Jumpers are in default positions: JP1=5V_STLK, JP2=ON, SW1=3V3.

What I already tried:

• Multiple USB cables and ports.

• “Connect under reset” procedure (RESET held while connecting).

• STM32CubeProgrammer CLI with -c port=SWD mode=UR reset=HWrst freq=1000 -e all → still fails.

• Verified my second board works with the same setup, so the PC, drivers, and CubeProgrammer are OK.

Questions:

1. Could the firmware I flashed have permanently disabled SWD (e.g., via Option Bytes)?

2. Is there another recovery method to force a full chip erase?

3. If not, should I treat this board as defective and request an RMA from ST eStore?

Thank you in advance for your guidance.

[STTwo-32]

Hello @Araleb and welcome to the ST Community.

To connect to your NUCLEO-WB05KZ, you should follow those steps:

1. Fit a jumper between the two upper pins of the JP1 on the MB2032 (on bootloader mood).
2. Open the STM32CubeProgrammer V2.20.0.
3. Connect the board to your PC.
4. Set the boot mood to UART, the parity to None, the baudrate to 115200 and the correct COM port: 
5. Click on the Connect button (you may need to click on the reset button).
6. After connection established, click on the Mass erase button:
7. (optional) If that didn't work, check the read unprotected option before step 5 and click on the Connect button that should perform a Mass erase: 

   Best Regards.

   STTwo-32